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SR780 Service Manual - Stanford Research Systems

1. Analog Input Board Parts List RefNo SRS Part No Component Description 5 00060 512 5 00060 512 5 00100 517 5 00023 529 5 00159 501 5 00023 529 5 00100 517 5 00100 517 5 00093 517 5 00093 517 5 00100 517 5 00100 517 5 00093 517 5 00093 517 5 00227 526 5 00093 517 5 00093 517 5 00134 529 5 00219 529 5 00023 529 5 00008 501 5 00005 501 5 00017 501 5 00008 501 5 00005 501 5 00017 501 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00134 529 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 5 00148 545 Service Guide 1 0U 1 0U 2 2U 1U 6 8P 1U 2 2U 2 2U 15U 15U 2 2U 2 2U 15U 15U 100U 15U 15U 100P 01U 1U 22P 150P 47P 22P 150P 47P 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 100P 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V 1000P 50V Cap Stacked Metal Film 50V 5 40 85c Cap Stacked Metal Film 50V 5 40 85c Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic Disc 50V 10 SL Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capaci
2. 3 4 3 8 3 9 3 9 3 10 3 10 3 10 3 10 3 11 3 13 3 13 3 14 3 15 3 16 3 16 3 17 3 17 3 18 3 19 3 19 3 19 3 20 3 21 3 22 3 23 SR780 Network Signal Analyzer 3 2 Service SR780 Network Signal Analyzer Service Guide Service 3 3 Before Proceeding With Service Warranty Service CAUTION Reset A Calibration Service Guide For warranty service or repair this product must be returned to a Stanford Research Systems authorized service facility Do not attempt any service without first contacting Stanford Research Systems or an authorized representative Replacement parts boards and assemblies are available only from Stanford Research Systems or its authorized representatives Potentially lethal voltages are present in this instrument This unit is to be serviced by qualified service personnel only There are no user serviceable parts inside Check the red LED at the top edge of Power Supply board The unit is safe only if the LED is OFF If the LED is ON then voltages are present within the unit USE CAUTION Use caution when checking circuits with the power on Always disconnect the power cord before replacing or servicing any component inside the chassis Reset the unit by turning the power off and back on while holding down the backspace key This clears the stored setup and re initializes the instrument If the problem is solved do not proceed to service any internal components If the pro
3. Connector BNC Connector BNC Connector BNC Connector BNC Connector BNC DIN Connector Female DIN Connector Female DIN Connector Female SMB Connector SMB Connector SMB Connector SMB Connector SMB Connector SMB Connector DIN Connector Female Connector Male Connector Male Connector Male Printed Circuit Board Jam Nut Washer lock Cable Assembly Ribbon Service Guide Parts List 4 35 Miscellaneous amp Chassis Assembly Parts List Miscellaneous and Chassis Assembly Parts List RefNo SRS Part No Component Description 3 00552 342 3 00552 342 3 00552 342 3 00552 342 3 00552 342 3 00552 342 3 00639 342 3 00639 342 0 00014 002 0 00043 011 0 00079 031 0 00081 032 0 00089 033 0 00098 042 0 00114 050 0 00135 050 0 00149 020 0 00150 026 0 00157 000 0 00167 023 0 00179 000 0 00180 000 0 00181 020 0 00185 021 0 00187 021 0 00195 020 0 00204 000 0 00209 021 0 00212 021 0 00248 026 0 00249 021 0 00256 043 0 00259 021 0 00280 050 0 00308 021 0 00327 050 0 00328 050 0 00329 050 0 00336 027 0 00351 029 0 0037 1 026 0 00377 004 0 00378 004 0 00382 000 0 00390 024 0 00391 010 0 00415 031 Service Guide 27C010 70DC 27C010 70DC 27C010 70DC 27C010 70DC 27C010 70DC 27C010 70DC 27C020 120 27C020 120 6J4 4 40 KEP 4 40X3 16 M F 320882 4 6 LOCK 10 1 8 18 7 5 8 18 4 40X1 4PF 4 40X1 4PF BNC PLUG 6 32X1 2RP RIGHT FOOT LEFT FOOT 6 32X1 4PF 6 32X3 8PP 4
4. 1 2W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Socket THRU HOLE Inductor Transformer Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Integrated Circuit Thru hole Pkg Crystal Oscillator GAL PAL I C Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg
5. 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX Service Guide SR780 Network Signal Analyzer 4 18 Parts List DSP Board Parts List RefNo SRS Part No Component Description 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 3 00004 301 3 00004 301 3 00204 301 3 00204 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 1 00239 135 1 00239 135 1 00241 141 1 00241 141 1 00234 109 1 00234 109 1 00239 135 3 00444 335 3 00196 335 3 00196 335 3 00196 335 3 00444 335 6 00180 60
6. 50PPM 4 00193 407 499 Resistor Metal Film 1 8W 1 50PPM 4 00193 407 499 Resistor Metal Film 1 8W 1 50PPM 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM 4 00143 407 102K Resistor Metal Film 1 8W 1 50PPM 4 00145 407 110 Resistor Metal Film 1 8W 1 50PPM 4 00145 407 110 Resistor Metal Film 1 8W 1 50PPM 4 00217 408 1 000K Resistor Metal Film 1 8W 0 1 25ppm 4 00217 408 1 000K Resistor Metal Film 1 8W 0 1 25ppm 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM 4 00375 407 348 Resistor Metal Film 1 8W 1 50PPM 4 00375 407 348 Resistor Metal Film 1 8W 1 50PPM 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM 4 00234 407 10 Resistor Metal Film 1 8W 1 50PPM 4 00203 407 Resistor Metal Film 1 8W 1 50PPM 4 00143 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00034 401 Resistor Carbon Film 1 4W 596 4 00192 407 4 00143 407 Service Guide Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 196 50PPM SR780 Network Signal Analyzer 4 28 Parts List Analog Input Board Parts List RefNo SRS Part No Component Description 4 00143 407 4 00138 407 4 0041 1 407 4 0041 1 407 4 00138 407 4 00696 407 4 00031 401 4 00031 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00329 407 4 00086 401 4 00192 407 4 00138 407 4 00440 407 4 00031 401 4 00022 401 4 00380 407 4 00556 407 4 00164 407 4 00556 407 4 00
7. Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Polyester Film 50V 5 40 85c Rad Cap Stacked Metal Film 50V 5 40 85c Cap Stacked Metal Film 50V 5 40 85c Cap Stacked Metal Film 50V 5 40 85c Capacitor Ceramic Disc 50V 10 SL Cap Stacked Metal Film 50V 5 40 85c Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Service Guide Parts List 4 25 Analog Input Board Parts List RefNo SRS Part No Component Description 5 00100 517 5 00134 529 5 00269 501 5 00023 529 5 00006 501 5 00093 517 5 00093 517 5 00093 517 5 00093 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00219 529 5 00219 529 5 00219 529 5 00219 529 5 00023 529 5 00098 517 5 00098 517 5 00219 529 5 00219 529 5 00219 529 5 00219 529 5 0021
8. Standoff Misc Components SR780 Network Signal Analyzer 4 14 Parts List Disk Card Parts List This section covers schematics MBKPL 24 in Chapter 5 Disk Card Parts List RefNo SRS Part No Component Description 5 00192 542 3 006 10 303 1 00234 109 1 00272 130 1 00116 130 22U MIN GREEN RT ANGLE 96 PIN RT ANGLE 34 PIN DI 4 PIN DI DISK DIN 5 20 PIN ELH VERT MEGAPLAT D D 1 00113 100 1 00242 130 7 00626 701 4 00098 401 680 0 00187 021 1 00141 171 1 00252 171 8 00034 850 4 40X1 4PP 5 PIN SIL 34 COND FLOPPY SR780 Network Signal Analyzer Cap Mini Electrolytic 50V 20 Radial LED T1 Package DIN Connector Male Connector Male Connector Male Connector Misc Connector Male Printed Circuit Board Resistor Carbon Film 1 4W 5 Screw Panhead Phillips Cable Assembly Ribbon Cable Assembly Ribbon Disk Drive Service Guide Parts List 4 15 DSP Board Parts List This section covers schematics D780 1 through D780 6 in Chapter 5 RefNo SRS Part No Value Component Description 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00148 545 1000P 50V Capacitor Monolythic Ceramic COG 1 5 00148 545 1000P 50V Capacitor Monolythic Cer
9. 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U 5 00218 529 120P Cap Monolythic Ceramic 50V 2096 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL 5 00022 501 001U Capacitor Ceramic Disc 50V 10 SL 5 00316 512 027U Cap Stacked Metal Film 50V 5 40 85c 5 00054 512 047U Cap Stacked Metal Film 50V 596 40 85c 5 00022 501 001U Capacitor Ceramic Disc 50V 10 SL 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL 5 00178 501 62P Capacitor Ceramic Disc 50V 10 SL 5 00178 501 62P Capacitor Ceramic Disc 50V 10 SL 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 0
10. 00852 420 4 00707 425 4 00422 421 4 00261 425 4 00261 425 4 00220 420 4 00244 421 4 00856 421 7 00522 701 3 00022 325 3 00022 325 4 00065 401 4 00065 401 4 00065 401 4 00065 401 4 00080 401 4 00080 401 4 00021 401 4 00080 401 01U AXIAL 01U AXIAL 01U AXIAL 2 2U 2 2U 2 2U 2 2U 2 2U 2 2U 2 2U 2 2U 2 2U 2 2U 10U 01U AXIAL 01U AXIAL 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 120 PIN RT ANGL 2 2KX7 82X8 82X8 82X8 2 2KX7 82X5 2 2KX9 2 2KX9 10KX8 10KX4 1 0KX5 MEGAPLAT CPU 2N3906 2N3906 3 3K 3 3K 3 3K 3 3K 47 47 47 SR780 Network Signal Analyzer Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Tantalum 35V 2096 Rad Capacitor Electrolytic 50V 20 Rad Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode DIN Connector Male Resistor Network SIP 1 4W 2 Common Resistor Network DIP 1 4W 2 8 Ind Resistor Network DIP 1 4W 2 8 Ind Resistor Network DIP 1 4W 2 8 Ind Resistor Network SIP 1 4W 2 Common Res Netw
11. 1 50PPM 4 00279 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00134 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00142 407 Resistor Metal Film 1 8W 1 50PPM 4 00031 401 Resistor Carbon Film 1 4W 5 Service Guide SR780 Network Signal Analyzer 4 30 Parts List Analog Input Board Parts List RefNo SRS Part No Component Description 4 00031 401 4 00031 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00896 407 4 00547 407 4 00705 407 4 00705 407 4 00896 407 4 00363 407 4 00893 407 4 00130 407 4 00166 407 4 00176 407 4 00130 407 4 00059 401 4 00031 401 4 00031 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00031 401 4 00045 401 4 00185 407 4 00161 407 4 00161 407 4 00031 401 4 00234 407 4 00188 407 4 00158 407 4 00395 407 4 00045 401 4 00031 401 4 00031 401 4 00330 407 4 00130 407 4 00158 407 4 00738 407 4 00158 407 4 00738 407 4 00696 407 4 00210 407 4 00158 407 SR780 Network Signal Analyzer Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbo
12. 1 8W 1 50PPM Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Voltage Reg TO 220 TAB Package Voltage Reg TO 220 TAB Package Voltage Reg TO 220 TAB Package Voltage Reg TO 220 TAB Package Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin SR780 Network Signal Analyzer 4 12 Parts List Power Supply Board Parts List RefNo SRS Part No Component Description 0 00168 023 0 00187 021 0 00231 043 0 00244 021 0 00316 003 6 32X5 16R 4 40X1 4PP 1 32 4 SHOULD 6 32X1 1 8PP PLTFM 28 CARD EJECTOR 60MM 12V K4 AC 34 10 PIN 18AWG OR 5 PIN 18AWG OR MAP55 4000 SR780 27 0 00373 000 0 00509 070 0 01046 003 1 00002 113 1 00033 113 6 00179 615 7 00541 720 SR780 Network Signal Analyzer Screw Roundhead Phillips Screw Panhead Phillips Washer nylon Screw Panhead Phillips Insulators Hardware Misc Fans amp Hardware Insulators Connector Amp MTA 156 Connector Amp MTA 156 Power Supply Fabricated Part Service Guide Parts List 4 13 System B
13. 2 Common 4 00675 456 2 000KX7 Res Network DIP 1 4W 0 1 4 00463 421 82X4 Res Network SIP 1 4W 2 Isolated 4 00243 420 1 0KX8 Resistor Network DIP 1 4W 2 8 Ind 4 00254 421 1 0KX3 Res Network SIP 1 4W 2 Isolated 4 00354 445 20 Pot Multi Turn Side Adjust 4 00015 445 100K Pot Multi Turn Side Adjust 4 00730 445 100 Pot Multi Turn Side Adjust 4 00015 445 100K Pot Multi Turn Side Adjust 4 00015 445 100K Pot Multi Turn Side Adjust 4 00731 445 200 Pot Multi Turn Side Adjust 4 00015 445 100K Pot Multi Turn Side Adjust 4 00760 445 500 Pot Multi Turn Side Adjust 4 00271 445 2 0K Pot Multi Turn Side Adjust 7 00616 701 SR780 ANALOG Printed Circuit Board 3 00022 325 2N3906 Transistor TO 92 Package 3 00021 325 2N3904 Transistor TO 92 Package 3 00021 325 2N3904 Transistor TO 92 Package 3 00021 325 2N3904 Transistor TO 92 Package 3 00021 325 2N3904 Transistor TO 92 Package 3 00021 325 2N3904 Transistor TO 92 Package 4 00071 401 33 Resistor Carbon Film 1 4W 5 4 00616 453 49 9 Resistor 2W 1 4 00071 401 33 Resistor Carbon Film 1 4W 5 4 00593 408 965 0K Resistor Metal Film 1 8W 0 1 25ppm 4 00515 407 31 6K Resistor Metal Film 1 8W 1 50PPM 4 00593 408 965 0K Resistor Metal Film 1 8W 0 1 25ppm 4 00515 407 31 6K Resistor Metal Film 1 8W 1 50PPM 4 00580 407 475 Resistor Metal Film 1 8W 1 50PPM 4 00580 407 475 Resistor Metal Film 1 8W 1 50PPM 4 00544 407 165 Resistor Metal Film 1 8W 1
14. 401 47 Resistor Carbon Film 1 4W 5 R 1111 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1112 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1113 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1114 4 00141 407 100 Resistor Metal Film 1 8W 1 50PPM R 1115 4 00215 407 909 Resistor Metal Film 1 8W 1 50PPM R 1116 4 00027 401 1 5K Resistor Carbon Film 1 4W 5 R 1117 4 00041 401 150 Resistor Carbon Film 1 4W 5 R 1201 4 00273 401 5 6K Resistor Carbon Film 1 4W 5 R 1202 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 1204 4 00090 401 560 Resistor Carbon Film 1 4W 5 R 1205 4 00090 401 560 Resistor Carbon Film 1 4W 5 R 1301 4 00022 401 1 0M Resistor Carbon Film 1 4W 5 R 1302 4 00062 401 270 Resistor Carbon Film 1 4W 5 R 1303 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 1304 4 00084 401 5 1K Resistor Carbon Film 1 4W 5 S0O1201 1 00232 150 52 PLCC TH Socket THRU HOLE SR780 Network Signal Analyzer Service Guide Parts List 4 9 Video lO Board Parts List RefNo SRS Part No Component Description 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 6 00178 621 3 00274 340 3 00598 340 3 00585 340 3 00585 340 3 0055 1 341 3 0055 1 341 3 00592 340 3 00592 340 3 00592 340 3 00592 340 3 00277 340 3 00274 340 3 00274 340 3 00591 340 3 00588 340 3 0024 1 340 3 00087 340 3 00122 325 3 00596 360 3 00645 340 3 00078 340 3 00079 3
15. 40X1 4PP 6 32X3 8PF REAR FOOT 4 40X3 8PP 6 32X2PP 10 32X3 8TRUSSP 6 32X1 1 2PP 6 SHOULDER 4 40X1 2 PP 9 18 4 40X7 8PP 8 18 WHITE 8 18 RED 8 18 BLACK 4X1 4PP B 4 40X1 4TRUSSPH 4 40X3 16PF SR760 830 780 CAP 760 830 780 CARD GUIDE 4 5 1 72X1 4 1 72X5 32X3 64 4 40X1 2 M F EPROM PROM I C EPROM PROM I C EPROM PROM I C EPROM PROM I C EPROM PROM I C EPROM PROM I C EPROM PROM I C EPROM PROM I C Power Entry Hardware Nut Kep Standoff Termination Tie Washer lock Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Screw Flathead Phillips Screw Black All Types Hardware Misc Screw Roundhead Phillips Hardware Misc Hardware Misc Screw Flathead Phillips Screw Panhead Phillips Screw Panhead Phillips Screw Flathead Phillips Hardware Misc Screw Panhead Phillips Screw Panhead Phillips Screw Black All Types Screw Panhead Phillips Washer nylon Screw Panhead Phillips Wire 18 UL1007 Stripped 3 8x3 8 No Tin Screw Panhead Phillips Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Screw Sheet Metal Screw Truss Phillips Screw Black All Types Knobs Knobs Hardware Misc Screw Slotted Nut Hex Standoff SR780 Network Signal Analyzer 4 36 Parts List Miscellaneous and Chassis Assembly Parts List RefNo SRS Part No Component Description
16. AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX Service Guide SR780 Network Signal Analyzer 4 4 Parts List CPU Board Parts List RefNo SRS Part No Component Description Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 5 00262 548 5 00262 548 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00038 509 5 00262 548 5 00262 548 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 1 00236 109 4 00707 425 4 00852 420 4 00852 420 4
17. Ch2 DispB Ch2 Upper Limit 90 dB Upper Limit 46 dBV 38 dBV 30 dBV 14 dBV 4 dBV 10 dBV 22 dBV 34 dBV Input Range 2 509 mVrms 6 302 mVrms 15 830 mVrms 99 881 mVrms 0 7934 Vrms 1 5830 Vrms 6 3021 Vrms 25 089 Vrms Flatness relative to 1 kHz Frequency 14 dBV 14 dBV 14 dBV 14 dBV 24 kHz 48 kHz 76 kHz 99 kHz SR780 Network Signal Analyzer 49 20 dBV 41 20 dBV 33 20 dBV 17 20 dBV 0 80 dBV 6 80 dBV 18 80 dBV 30 80 dBV Lower Limit DispA Chl DispB Ch2 48 80 dBV 40 80 dBV 32 80 dBV 16 80 dBV 1 20 dBV 7 20 dBV 19 20 dBV 31 20 dBV Upper Limit 17 20 dBV 17 20 dBV 17 20 dBV 17 20 dBV 16 80 dBV 16 80 dBV 16 80 dBV 16 80 dBV SR780 Performance Test Record 4 Amplitude Accuracy and Flatness Continued Flatness relative to 1 kHz Input Range Frequency 22 dBV 24 kHz 22 dBV 48 kHz 22 dBV 72 kHz 22 dBV 96 kHz Amplitude Linearity Input Range Calibrator Ampl Lower Limit DispA Chl DispB Ch2 Performance Tests 1 33 Page 2 of 3 18 80 dBV 18 80 dBV 18 80 dBV 18 80 dBV Lower Limit DispA Chl DispB Ch2 Upper Limit 19 20 dBV 19 20 dBV 19 20 dBV 19 20 dBV Upper Limit 22 dBV 6 3021 Vrms 1 1207 Vrms 141 09 mVrms 22 361 mVrms 3 544 mVrms Anti Alias Filter Attenuation 18 80 dBV 3 80 dBV 14 20 dBV 30 20 dBV 46 20 dBV Input Frequency DispA Ch
18. Frequency 1 gt 1 0 2 4 Select KHz Enter Input Chl Input Range lt Ch2 Input Range 2 Enter Auto Scale A Auto Scale B Use the knob to move the marker to 1 024 kHz The amplitude should be 6 dBV Marker Ref Marker now reads relative to the signal amplitude Input Chl Input Mode Ch2 Input Mode gt Select A B Enter Do not move the marker The marker reading is the common mode rejection ration CMRR If the reading is below 100 dB then do not make any adjustment If the reading is above 100 dB then adjust the High Gain CMR pot to minimize the reading see Fig 3 3 Press Input Chl Input Range lt Ch2 Input Range gt 0 Enter Chl Input Mode Ch2 Input Mode gt Select A Enter Auto Scale A Auto Scale B Marker Ref Marker now reads absolute signal amplitude Use the knob to move the marker to 1 024 kHz The amplitude should be 6 dBV Marker Ref Marker now reads relative to the signal amplitude SR780 Network Signal Analyzer 3 26 Service Input Chl Input Mode lt Ch2 Input Mode gt Select A B Enter Do not move the marker The marker reading is the common mode rejection ration CMRR If the reading is below 80 dB then do not make any adjustment If the reading is above 80 dB then adjust the Low Gain CMR pot to minimize the reading see Fig 3 3 14 Remove the cables from the A and B inputs Connect a 50Q termination to
19. Performance Tests SR780 Network Signal Analyzer Performance Tests 10 Sine Source This test measures the source sine output Setup Connect the Source output to the Ch1 A input Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Source Amplitude 1 gt 1 0 0 0 Enter Auto Range Chl and wait until the range stops changing Auto Scale A Marker Max 3 Record the marker Y reading for DisplayA 4 Press Amplitude 1 gt 1 0 0 Enter 5 Record the marker Y reading for DisplayA 6 Press Amplitude 1 gt 1 0 Enter 7 Record the marker Y reading for DisplayA 8 Press Amplitude 1 gt 1 0 0 0 Enter 9 For each of the frequencies below perform steps 9a and 9b Frequency 20 48 kHz 40 96 kHz 61 44 kHz 81 92 kHz 99 072 kHz 1 29 SR780 Network Signal Analyzer 1 30 Performance Tests a Press Frequency 1 gt Enter the frequency from the table Marker Max b Record the marker Y reading for DisplayA 8 This completes the source sine test Enter the results of this test in the test record SR780 Network Signal Analyzer Performance Tests 1 31 11 Harmonic Distortion This test measures the harmonic distortion of the analyzer source and inputs Setup Connect the source output to the Chl A and Ch2 A inputs of the analyzer Procedure 1 Reset the unit by pressing System
20. Resistor Metal Film 1 8W 1 50PPM 4 00161 407 Resistor Metal Film 1 8W 1 50PPM 4 00188 407 Resistor Metal Film 1 8W 1 50PPM 4 00031 401 Resistor Carbon Film 1 4W 596 Service Guide SR780 Network Signal Analyzer 4 20 Parts List DSP Board Parts List RefNo SRS Part No Component Description 4 00781 402 4 00781 402 4 00034 401 4 00034 401 4 00471 401 4 00471 401 4 00471 401 4 00060 401 4 00060 401 4 00471 401 4 00021 401 1 00231 150 6 00137 601 6 00009 610 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 3 00577 340 6 00177 621 3 00699 343 3 00597 340 3 00597 340 3 00597 340 3 00265 340 3 00265 340 3 00265 340 3 00265 340 3 00265 340 3 00265 340 3 00265 340 3 00265 340 3 00488 340 3 00488 340 3 00350 340 3 00531 340 3 00532 340 3 00130 340 3 00130 340 3 00130 340 3 00423 340 3 0024 1 340 3 0037 1 340 82 82 82 240 240 82 1 0K PGA 223 PIN 15MH T1 1 X65 TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK ADSP21020KG 133 33 333 MHZ SR780 U301 7204L25TP 7204L25TP 7204L25TP 74HC595 74HC595 74HC595 74HC595 74HC595 74HC595 74HC595 74HC595 74HC597 74HC597 74ALS04 AD766JN AD744 5532A 5532A 5532A 5534A AD7528JN DG444 SR780 Network Signal Analyzer Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp
21. SIMM SR780 35 SR780 39 SR780 44 SR780 46 SR780 47 SR780 48 9 Z AXIS GENERIC DBL SIDED 1 2 4 40X1 4PP 6 32X3 8PF 8MB 2X32 60 32MB 8X32 60 2K SR770 11 SR780 8 SR780 9 SR780 15 SR780 26 SR780 25 Fabricated Part Fabricated Part Fabricated Part Lexan Overlay Fabricated Part Fabricated Part Fabricated Part Keypad Conductive Rubber Printed Circuit Board Printed Circuit Board Injection Molded Plastic Extrusion Machined Part Machined Part Machined Part Fabricated Part CRT Display Product Labels Tape All types Screw Panhead Phillips Screw Flathead Phillips SIMM Dynamic Ram SIMM Dynamic Ram Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part SR780 Network Signal Analyzer 4 38 Parts List SR780 Network Signal Analyzer Service Guide 5 1 Chapter 5 Schematic Diagrams In This Chapter Assembly CPU Board MCPU 1 through MCPU 9 Video IO Board MVID 10 through MVID 14 Power Supply MPWR 1 through MPWR 2 System Backplane MBKPL 20 through MBKPL 23 Disk Card MBKPL 24 Keypad Board MKEY 1 DSP Board D780 1 through D780 9 Analog Input Boards A780 1 through A780 7 Analyzer Backplane M780 1 through M780 4 Demo Filter F780 1 Service Guide SR780 Network Signal Analyzer 5 2 Schematic Diagrams SR780 Network Signal Analyzer Service Guide
22. Service Guide Parts List 4 21 DSP Board Parts List RefNo SRS Part No Component Description 3 00423 340 5534A Integrated Circuit Thru hole Pkg 3 00383 340 LM6321 Integrated Circuit Thru hole Pkg 3 00423 340 5534A Integrated Circuit Thru hole Pkg 3 0011 7 325 78L12 Transistor TO 92 Package 3 00123 325 79L12 Transistor TO 92 Package 3 00089 340 LF357 Integrated Circuit Thru hole Pkg 3 00461 340 OPA2604 Integrated Circuit Thru hole Pkg 3 00262 340 74HC86 Integrated Circuit Thru hole Pkg 3 00211 340 LT1016 Integrated Circuit Thru hole Pkg 3 00087 340 LF347 Integrated Circuit Thru hole Pkg 3 00241 340 AD7528JN Integrated Circuit Thru hole Pkg 3 00116 325 78L05 Transistor TO 92 Package 3 001 16 325 78L05 Transistor TO 92 Package 3 00122 325 79L05 Transistor TO 92 Package 3 00695 343 SR780 U701 GAL PAL I C 3 00696 343 SR780 U702 GAL PAL I C 3 00697 343 SR780 U703 GAL PAL I C 3 00698 343 SR780 U704 GAL PAL I C 6 00110 621 30 208 MHZ Crystal Oscillator 6 00181 621 30 933 MHZ Crystal Oscillator 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg 3 00603 340 74ALS573 Integrated Circuit Thru hole Pkg 3 00584 340 7T4ACT574 Integrated Circuit Thru hole Pkg 3 00584 340 7T4ACT574 Integrated Circuit Thru hole Pkg 3 00049 340 74HC74 Integrated Circu
23. an 80C186XL or 80C186EA microcontroller which integrates a fast 16 bit processor counter timers interrupt controller DMA controller and I O decoding into a single component The 80C186 is clocked at 40 00 MHz by crystal oscillator U103 The external clock period is 2 oscillator cycles or 20 0 MHz The data and lower 16 bits of address are multiplexed on processor lines ADO AD15 U201 U202 U203 latch the address A0 A19 at the beginning of each memory or I O cycle U204 and U205 are bi directional data bus drivers which are active during the data read write portion of each memory or I O cycle U201 U205 provide the on board System bus Memory Map The 80C186 can address 1 Mbyte of memory and 64k of I O space The memory is mapped into 5 blocks Each block has 2 sockets one for the low byte and one for the high byte of data U301 U304 are 128 kbyte EPROMS mapped from 80000H to FFFFFH EPROMS U305 and U306 are mapped from 50000H to 7FFFFH for a total of 704 kbytes of program ROM U401 U404 are 128 kbyte CMOS static RAMs mapped from 00000H to 4FFFFH 320 kbytes U401 and U402 256 kbytes are battery backed up I O Map Service Guide U209 and U210 are the data bus drivers for the off board I O Expansion bus U206 and U207 are the data bus drivers for the off board External DSP bus U208 is the address driver for the External bus U213 is a PAL which enables the correct bus drivers depending upon the I O address space being acces
24. behind the CRT contains the power supply main CPU card and the video IO card The cards are interconnected by a backplane board under the card cage The disk drive is mounted to a small board beneath the CRT This card can be removed from the front The keypad connects to the disk board at the front of the chassis Figure 3 1 System Components Chassis Top View CPU Video IO Power Supply System Backplane CRT Enclosure Disk Card Keypad Board Disk Drive Front SR780 Network Signal Analyzer Service Guide Service 3 9 Analyzer Components The analyzer section is in the right half of the chassis directly behind the keypad A card cage contains the DSP board and two identical analog input boards The analyzer boards are interconnected by a backplane board under the card cage This backplane extends all the way to the front panel BNC connectors The analyzer backplane connects to the system backplane via two short cables at the center of the chassis just behind the CRT Figure 3 2 Analyzer Components Chassis Top View DSP Board Chl Analog Input Board Ch2 Analog Input Board Analyzer Backplane Front Schematic Diagram Locations Schematic diagrams are located in Chapter 5 Board Assembly Schematic s see Chapter 5 CPU Board MCPU 1 through MCPU 9 Video IO Board MVID 10 through MVID 14 Power Supply MPWR 1 through MPWR 2 System Backplane MBKPL 20 through MBKPL 23 Disk Card MBKPL 24 Keypad Bo
25. by a linear power supply The transformer on the rear panel provides two 41VAC center tapped secondaries and two 26V AC secondaries The 41V AC secondaries are used to generate 20VDC supplies for the analog inputs and the source output The 26V AC secondaries generate 30V isolated supplies for the ICP power SR780 Network Signal Analyzer Service Guide Service Guide Circuit Description 2 11 Bridge rectifiers D1 D4 and D5 D8 rectify the 41V AC secondaries Filter capacitors C10 C11 and C20 C21 provide filtered 28 VDC Resistors provide a bleed current on all of the unregulated supply filter capacitors Because of the large capacitance in this circuit the time for the voltages to bleed to zero is about a minute after the power is turned off The 20VDC supplies are generated by voltage regulators U10 U11 and U20 U21 These supplies are floating on this board The ground reference for 20V D source power is on the DSP board This supply floats if no DSP board is plugged in The ground reference for 20V_A analog power is on the analog input boards This supply floats if no analog input board is plugged in The 30V supplies are very low current and only require small 100 mA regulators U30 and U40 SR780 Network Signal Analyzer 2 12 Circuit Description DSP Board This section covers schematics D780 1 through D780 6 in Chapter 5 The DSP board takes digital inputs from the A D Converters on the Analog Input boards and performs
26. card ejectors to release the board and pull the board up and out Use the DVM to verify that the Trigger Input BNC center conductor and shield are connected to the rear most SMB jack at the bottom of the card cage directly behind the Trigger Input The BNC center conductor connects to the female center of the SMB jack The BNC shield connects to the SMB shield If the connection is OK follow Procedure F1 to replace the DSP board Otherwise contact SRS for more information Service Procedure F6 Checking the Source 1 2 Check the source output on the oscilloscope Reset the unit by holding down the backspace key while turning the power ON Connect the Source Output to the oscilloscope In the Source menu choose Sine A 10 24 kHz 1 0 Vpp sine wave should be displayed on the oscilloscope If not continue Turn the power OFF Remove the power cord from the power entry module SR780 Network Signal Analyzer Service Guide Service 3 21 Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 3 2 to locate the DSP board in the Analyzer card cage closest to the CRT Remove the card cage cover by loosening the five screws in the cover Remove the DSP
27. display the System menu and then press lt Preset gt and Enter to confirm The unit will perform power up tests and then assume the default settings Each test generally starts with a reset Serial Number If you need to contact Stanford Research Systems please have the serial number of your unit available The serial number is printed on a label affixed to the rear panel The serial number is also displayed on the screen when the unit is powered on Firmware Revision The firmware revision code is displayed on the screen when the unit is powered on SR780 Network Signal Analyzer 1 4 Performance Tests Necessary Equipment The following equipment is necessary to complete the performance tests The suggested equipment or its equivalent should be used Frequency Synthesizer Freq Range 1 Hz to 1 MHz Freq Accuracy better than 5 ppm Amplitude Accuracy 0 2 dB from 1 Hz to 100 kHz Harmonic Distortion lt 65 dBc Spurious lt 55 dBc Recommended SRS DS345 AC Calibrator Freq Range 10 Hz to 100 kHz Amplitude 1 mV to 10 V Accuracy 0 196 External phase locking capability Recommended Fluke 5200A Feedthrough Terminations Impedance 500 Warm Up The analyzer should be turned on and allowed to warm up for at least an hour before any tests are performed The self test does not require any warm up period It is necessary to turn the unit off and on to reset it As long as the unit is powered within a minute this will not affect the te
28. fast as possible Data is read 16 bits at a time When data is required for the display the even data bits are latched into U1008 and the odd data bits are latched into U1009 U1008 and U1009 are parallel to serial converters The video data is shifted out at 19 59 MHz and synchronized by U1013 U1014A synchronizes the Display Enable to disable the video data except during active display times The display consists of two layers or planes Data on the front plane appears in front of data on the rear plane Each pixel requires two bits of information The even bit is drawn on the front plane and the odd bit is drawn on the rear plane The even bit disables the odd bit which puts it in front U1012 handles the layering logic The display planes make it simple to draw a graph in front of a grid The two display planes each have their own display brightness This gives the display a three dimensional appearance Current sources Q1101 and Q1102 set the brightness for the front and rear planes U1101 is a dual DAC which programs the two current sources Disk Controller U1201 1s a DP8473 disk controller which integrates all of the functions of the PC disk interface into a single IC All motor controls read and write signals and data are controlled by the DP8473 A DMA channel is used to send and receive data from the controller in order to satisfy the disk drive timing SR780 Network Signal Analyzer Service Guide Circuit Description 2 9 GPIB
29. state of the timing generator when a trigger signal is detected The timing generator interrupts the DSP whenever the serial ports A D and D A are ready every sample time The trigger is also synchronized to the state machine and generates an interrupt I O Interface The A D converters on the analog boards send a serial data stream to the DSP board Each analog board uses a dual 16 bit converter with both channels digitizing the signal Each board returns two data streams for a total of four A D channels U401 U404 and U405 U408 are 32 bit serial to parallel converters each receiving two 16 bit data channels from a single analog board U409 U410 is a 16 bit parallel to serial converter which sends DSP data to the source D A converter Trigger The Trigger input can be a TTL level signal or an analog signal T601 provides some common mode rejection for the trigger input Relay K602 selects TTL or Analog Level Trigger Relay K601 allows the trigger signal to come from the output of the analog front end amplifiers or the external TRIGGER front panel BNC Trigger signals pass through the XOR gate U602C where rising or falling edge trigger slope is selected TTL triggers proceed directly to the XOR gate via some input protection Analog level signals are first converted to a TTL signal via high speed comparator U603 At the heart of the trigger input is the analog high speed comparator U603 LT1016 The input is buffered by U601A and limite
30. test record at the end of this section SR780 Network Signal Analyzer 1 22 Performance Tests SR780 Network Signal Analyzer 8 Phase Accuracy Setup We will use the frequency synthesizer to provide the signal Procedure Performance Tests 1 23 This test measures the phase accuracy of the analyzer This test measures the phase of a signal relative to the trigger Connect the output of the frequency synthesizer to the Trigger Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 10 240 kHz and an amplitude of 500 mVrms 3 Press the keys in the following sequence Input Chl Input Range gt 2 lt dBV gt lt Ch2 Input Range gt 2 lt dBV gt Chl Coupling Select AC Enter lt Ch2 Coupling Select AC Enter Trigger Trigger Source Select Ch1 Enter Trigger Mode Select Auto Arm Enter Auto Scale A Auto Scale B Marker lt Marker gt Select Link Enter Marker Max Display Setup lt View gt Select Phase Enter SR780 Network Signal Analyzer 1 24 Performance Tests Active Display Make DisplayB the active display Display Setup lt View gt Select Phase Enter Auto Scale A Auto Scale B Average lt Avgs gt 1 0 Enter lt Average M
31. the Chl Ch2 A input This shorts the input to ground so the analyzer s own DC offset is measured Input Chl Input Range Ch2 Input Range gt 5 0 Enter Chl Input Mode Ch2 Input Mode Select A Enter Marker Ref Marker now reads absolute signal amplitude Use the knob to move the marker to 0 Hz The marker position should display 0 Hz The marker reading is the DC offset Auto Scale A Auto Scale B If the marker reading is less than 85 dBV remember 80 dBV is greater than 85 dBV and 90 dBV is less than 85 dBV then proceed to the next step If the reading is greater than 85 dBV adjust the High Gain Offset pot to minimize the marker reading see Fig 3 3 15 Press 16 17 18 19 Input Chl Input Range lt Ch2 Input Range gt 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 50 dBV remember 40 dBV is greater than 50 dBV and 60 dBV is less than 50 dBV then proceed to the next step If the reading is greater than 50 dBV adjust the Low Gain Offset pot to minimize the marker reading see Fig 3 3 This completes the adjustment procedure Replace the small shield at the front Replace the card cage cover and tighten the cover screws Replace the top lid and refasten the eight lid screws Reset the unit by turning the power ON while holding down the backspace key If the DC offset or Common Mode Rejection are still a problem re
32. the lid towards the back and upwards SR780 Network Signal Analyzer Service Guide Service 3 11 See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding Release the bar which secures the boards in place Remove the two screws which secure the power supply shield to the rear panel These are located on the rear panel directly in back of the power supply board Remove the Power Supply board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Replace the two screws which secure the power supply shield to the rear panel Replace the bar which secures the boards in place Replace the top lid and refasten the eight lid screws Service Procedure A2 Power Supply Check Service Guide 1 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Check the AC power source for the correct line voltage either 100V 120V 220V or 240V AC rms Make sure that the power cord is OK Verify that the Line Voltage Selector card located in the rear pane
33. 0 3 00143 340 3 00143 340 3 00130 340 3 00461 340 3 00385 340 3 00423 340 3 00385 340 3 00423 340 3 00423 340 3 0037 1 340 3 0037 1 340 3 00143 340 3 00130 340 3 00130 340 3 00130 340 3 00130 340 3 00423 340 3 00130 340 3 00130 340 3 00130 340 3 00130 340 3 00130 340 3 00130 340 3 00886 340 3 00116 325 3 00059 340 3 00091 340 3 00089 340 3 00089 340 3 00130 340 3 00385 340 3 00143 340 3 00143 340 3 00392 340 3 00155 340 3 00091 340 3 00118 325 TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK NPD5564 NPD5566 OPA2604 OPA2604 5534A LM393 LM393 5532A OPA2604 74HC4053 5534A 74HC4053 5534A 5534A DG444 DG444 LM393 5532A 5532A 5532A 5532A 5534A 5532A 5532A 5532A 5532A 5532A 5532A OPA2134 78L05 7542 LF412 LF357 LF357 5532A 74HC4053 LM393 LM393 PCM1750P 74HC04 LF412 78L15 SR780 Network Signal Analyzer Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integ
34. 0 00417 057 0 0047 1 021 0 00472 018 0 00481 000 0 00500 000 0 00501 042 0 00502 000 0 00503 000 0 00505 064 0 00506 000 0 00507 070 0 00508 000 0 00517 000 0 00519 027 0 00523 048 0 00525 050 0 00527 050 0 00536 032 0 00598 031 0 00618 025 1 00120 113 1 00138 130 1 00141 171 1 00153 113 1 00246 130 1 00252 171 1 00253 171 1 00254 113 1 00273 171 1 00274 171 2 00034 220 2 00040 211 3 00600 341 4 00541 435 5 00298 568 5 00334 569 6 00043 611 6 00176 610 7 00124 720 7 00539 720 7 00540 720 7 00544 720 7 00545 720 7 00546 720 7 00547 720 7 00549 720 7 00550 720 7 00551 721 7 00552 721 7 00553 720 GROMMET STRIP 4 40X1 PP 1 329631 2 BUMPER CORD WRP 554808 1 1 329632 2 CARD GUIDE 6 CARD GUIDE 2 5 10 32X1 4 HANDLES 90MM 12V CARD GUIDE 5 BINDING POST 4X3 16PP B 5 5 8 18 8 1 4 18 GRN 13 18 31894 4 40X1 3 8 M F 10 32 X 5 8 3 PIN 18AWG OR 5 PIN SI 5 PIN SIL 11 PIN 18AWG OR 20 PIN ELH SHR 34 COND 20 COND 2 PIN 22AWG RD 10 COND DIL 20 COND X8 ENA1J B20 DPDT 128KX8 20 130V 1200A 01U 1U T35 1 5A 3AG SR780 TRANSCOVER2 MOD SR780 5 SR780 6 SR780 10 11 SR780 12 SR780 13 SR780 14 SR780 16 SR780 17 SR780 18 SR780 19 SR780 20 SR780 Network Signal Analyzer Grommet Screw Panhead Phillips Jam Nut Hardware Misc Hardware Misc Washer lock Hardware Misc Hardware Misc Screw Socket Head Shoulder Hardware Misc Fans amp Hardware Ha
35. 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 3 00149 329 3 00141 329 3 00149 329 3 00141 329 3 00096 340 3 00096 340 0 00121 050 0 00127 050 Service Guide 120 PIN RT ANGL 5 PIN WHITE 10 PIN WHITE 10KX4 SR780 P S 2 2K 2 2K 243 3 65K 243 3 65K 2 2K 2 2K 243 3 65K 243 3 65K 10K 243 5 62K 10K 243 5 62K TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK LM317T LM337T LM317T LM337T LM317L LM317L 2 1 2 18 4 18 RED DIN Connector Male Header Amp MTA 156 Header Amp MTA 156 Res Network SIP 1 4W 2 Isolated Printed Circuit Board Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp 1 2W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp 1 2W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film
36. 03B provides common mode feedback and maintains a constant drain current in each FET U105 provides the single ended output The gain of the front end is either 10 dB or 20 dB as selected by relay K107 When a gain of 10 dB is selected the offset and CMR are adjusted via P104 and P103 respectively When a gain of 20 dB is selected offset and CMR are adjusted via P102 and P101 respectively Gain Stages And Attenuators Collectively the front end amplifier gain stages and attenuators provide sensitivity ranges from 50 dBV to 34 dBV This is accomplished through the front end amplifier two gain stages and a resistive ladder attenuator Service Guide SR780 Network Signal Analyzer 2 16 Circuit Description The two gain stages are identical inverting amplifiers Each has selectable gain of 10 dB 0 dB 10 dB or 20 dB To achieve the desired gain the front end attenuator and amplifier and these two gain stages are cascaded together The signal path always includes the same number of amplifiers The resistive ladder attenuator R211 R216 provides attenuation from OdB to 10 dB in 2 dB steps This improves the gain resolution U206 is the buffered amplifier output Comparators U220 and U392 detect overload and half scale amplifier output based upon the A D converter reference voltage Anti Aliasing Filter To prevent aliasing the input signal passes through a low pass filter so that all frequency components greater than half the sampling fre
37. 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX Service Guide SR780 Network Signal Analyzer 4 8 Parts List RefNo SRS Part No Value Component Description C 1447 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX C 1450 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1451 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1452 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1453 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 1454 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad J 1401 1 00236 109 120 PIN RT ANGL DIN Connector Male N 1001 4 00334 42
38. 24 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00041 509 220U Capacitor Electrolytic 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00479 301 MUR410 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 0001 1 303 RED LED T1 Package 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode SR780 Network Signal Analyzer Service Guide Parts List 4 11 Power Supply Board Parts List RefNo SRS Part No Component Description 1 00236 109 1 00039 116 1 00114 116 4 00244 421 7 00526 701 4 00618 402 4 00618 402 4 00522 407 4 00444 407 4 00522 407 4 00444 407 4 00618 402 4 00618 402 4 00522 407 4 00444 407 4 00522 407 4 00444 407 4 00034 401 4 00522 407 4 00705 407 4 00034 401 4 00522 407 4 00705 407 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1
39. 29 5 00134 529 5 00219 529 1 00233 120 1 00233 120 1 00233 120 1 00233 120 1 00233 120 1 00233 120 1 00235 108 1 00235 108 1 00235 108 1 00224 141 1 00224 141 1 00224 141 1 00224 141 1 00224 141 1 00224 141 1 00235 108 1 00272 130 1 00272 130 1 00251 130 7 00797 701 0 00472 018 0 00501 042 1 00252 171 01U 01U 100P 01U 01U 100P 01U 01U 100P 01U 01U 100P 01U 01U 100P 100P 01U RT ANGLE RT ANGLE RT ANGLE RT ANGLE RT ANGLE RT ANGLE 96 PIN VERTICAL 96 PIN VERTICAL 96 PIN VERTICAL STRAIGHT PLUG STRAIGHT PLUG STRAIGHT PLUG STRAIGHT PLUG STRAIGHT PLUG STRAIGHT PLUG 96 PIN VERTICAL 34 PIN DI 34 PIN DI 10 PIN DIL SR785 BACKPLANE 1 329631 2 1 329632 2 34 COND SR780 Network Signal Analyzer Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Cap Monolythic Ceramic 50V 2096 Z5U Connector BNC
40. 3 4 00270 425 4 00262 425 4 00262 425 4 00856 421 4 00852 420 4 00265 421 4 00690 421 4 00767 420 4 00767 420 7 00494 701 3 00022 325 3 00022 325 4 00029 401 4 00471 401 4 00471 401 4 00079 401 4 00079 401 4 00177 407 4 00177 407 4 00771 407 4 00163 407 4 00409 408 4 00409 408 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1N4148 1N4148 1N5230 1N5230 1N4148 1N4148 1N4148 1N4148 72 PIN SIMM 72 PIN SIMM RT ANGLE JACK RT ANGLE JACK 96 PIN RT ANGLE 96 PIN RT ANGLE 72 PIN SIMM BS 211 DC5 GF HS 212S 5 HS 212S 5 HS 212S 5 BS 211 DC5 GF 560U 1 0KX5 100X7 100X7 1 0KX5 82X8 100X4 3 3KX4 270X8 270X8 SR780 DIGITAL 2N3906 2N3906 1 8K 82 82 SR780 Network Signal Analyzer Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Diode Diode Diode Diode Diode Diode Diode Diode Connector Card Edge Connector Card Edge SMB Connector SMB Connector DIN Connector Male DIN Connector Male Connector Card Edge Relay Relay Relay Relay Relay Inductor Axial Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Res Network SIP 1 4W 2 Isolated Resistor Network DIP 1 4W 2 8 Ind Res Network S
41. 40 3 00051 340 8 00091 860 3 001 10 340 3 00109 340 3 00342 340 3 00342 340 6 00068 620 6 00037 620 0 00373 000 Service Guide TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK 19 590 MHZ 74AC74 63484P 98 74ACT573 74ACT573 128KX8 70 128KX8 70 7TAACT299 74ACT299 74ACT299 7TAACT299 7AHC11 74AC74 74AC74 T4ACT04 74ACT08 AD7528JN LF347 79L05 DP8473AV NAT9914BPD DS75160A DS75161A 74HCU04 SR215 MC1489 MC1488 74ALS138 74ALS138 24 000 MHZ 3 6864 MHZ CARD EJECTOR Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Crystal Oscillator Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg STATIC RAM I C STATIC RAM I C Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Transistor TO 92 Package Integrated Circuit Surface Mount Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg SRS sub
42. 5 10KX5 Resistor Network SIP 1 4W 2 Common N 1101 4 00284 421 1 0KX4 Res Network SIP 1 4W 2 Isolated N 1102 4 00863 421 1 2KX4 Res Network SIP 1 4W 2 Isolated N 1201 4 00221 425 150X5 Resistor Network SIP 1 4W 2 Common PC1 7 00523 701 MEGA VIDEO Printed Circuit Board Q 1001 3 00021 325 2N3904 Transistor TO 92 Package Q 1002 3 00022 325 2N3906 Transistor TO 92 Package Q 1101 3 00022 325 2N3906 Transistor TO 92 Package Q 1102 3 00022 325 2N3906 Transistor TO 92 Package Q 1103 3 00022 325 2N3906 Transistor TO 92 Package Q 1104 3 00022 325 2N3906 Transistor TO 92 Package Q 1105 3 00022 325 2N3906 Transistor TO 92 Package Q 1106 3 00022 325 2N3906 Transistor TO 92 Package R 1001 4 00088 401 51K Resistor Carbon Film 1 4W 5 R 1002 4 00034 401 10K Resistor Carbon Film 1 4W 5 R 1003 4 00021 401 1 0K Resistor Carbon Film 1 4W 5 R 1004 4 00785 402 100 Resistor Carbon Comp 1 2W 5 R 1101 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1102 4 00080 401 47 Resistor Carbon Film 1 4W 5 R 1103 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1104 4 00165 407 200 Resistor Metal Film 1 8W 1 50PPM R 1105 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1106 4 00141 407 100 Resistor Metal Film 1 8W 1 50PPM R 1107 4 00215 407 909 Resistor Metal Film 1 8W 1 50PPM R 1108 4 00027 401 1 5K Resistor Carbon Film 1 4W 5 R 1109 4 00472 407 806 Resistor Metal Film 1 8W 1 50PPM R 1110 4 00080
43. 7 5 00100 517 5 00023 529 5 00023 529 5 00100 517 5 00100 517 5 00023 529 5 00023 529 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00023 529 5 00100 517 5 00100 517 5 00219 529 5 00049 566 5 00056 512 5 00056 512 5 00056 512 5 00317 501 5 00056 512 5 00134 529 5 00134 529 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00023 529 1000P 50V 01U 01U 1U 1U 2 2U 2 2U 1U 1U SR780 Network Signal Analyzer Capacitor Monolythic Ceramic COG 1 Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad
44. 764 407 4 00380 407 4 00556 407 4 00164 407 4 00556 407 4 00764 407 4 00568 407 4 00543 407 4 00873 407 4 00144 407 4 00874 407 4 0067 1 407 4 00059 401 4 00158 407 4 00158 407 4 00553 407 4 00553 407 4 00031 401 4 00031 401 4 00031 401 4 00031 401 4 00034 401 4 00142 407 4 00348 407 4 00765 407 4 00475 407 4 00748 408 SR780 Network Signal Analyzer Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM R
45. 8 Circuit Description Video IO Board This section covers schematics MVID 10 through MVID 14 in Chapter 5 The Video IO board contains the display generation hardware the GPIB and RS232 interfaces and the disk controller Video Graphics Interface The video graphics interface is centered around U1003 an HD63484 graphics controller The HD63484 generates the video sync signals controls the video memory draws graphic primitives such as lines circles polygons etc and performs many memory to memory functions The HD63484 relieves the 80C186 from having to calculate each video image and greatly increases display speed Commands and data are sent from the 80C186 to the HD63484 using a DMA channel This allows the HD63484 to process commands without having to wait for the 80C186 to send them U1006 and U1007 are 128 kbyte RAMs which make up the 256k video memory Each pixel is made up of 2 bits The video screen is 800H by 600V and requires 120 000 bytes of memory The remaining memory is used to store patterns and fonts as well as a second display screen The data and address are multiplexed and U1004 and U1005 are the address latches Memory is accessed twice during each display cycle The first access reads the 16 bits of video data for the current display cycle The second access 1s used by the controller for drawing purposes During the drawing access data at any address may be read or written This allows drawing to take place as
46. 8 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX
47. 9 529 5 00100 517 5 00100 517 5 00219 529 5 00219 529 5 00100 517 5 00287 562 5 00287 562 5 00093 517 5 00038 509 5 00038 509 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00038 509 5 00023 529 5 00100 517 5 00098 517 5 00098 517 5 00098 517 5 00098 517 5 00023 529 5 00023 529 5 00100 517 5 00100 517 Service Guide Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic Disc 50V 10 SL Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic Disc 50V 10 SL Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Cap N
48. 93 517 15U Capacitor Tantalum 35V 2096 Rad 5 00093 517 15U Capacitor Tantalum 35V 2096 Rad 5 00093 517 15U Capacitor Tantalum 35V 2096 Rad 5 00093 517 15U Capacitor Tantalum 35V 2096 Rad 5 00093 517 15U Capacitor Tantalum 35V 2096 Rad 5 00098 517 10U Capacitor Tantalum 35V 20 Rad 5 00098 517 10U Capacitor Tantalum 35V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad 5 00038 509 10U Capacitor Electrolytic 50V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50
49. IP 1 4W 2 Isolated Res Network SIP 1 4W 2 Isolated Resistor Network DIP 1 4W 2 8 Ind Resistor Network DIP 1 4W 2 8 Ind Printed Circuit Board Transistor TO 92 Package Transistor TO 92 Package Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 0 1 25ppm Resistor Metal Film 1 8W 0 1 25ppm Service Guide Parts List 4 19 RefNo SRS Part No Value Component Description 4 00467 407 Resistor Metal Film 1 8W 1 50PPM 4 00193 407 Resistor Metal Film 1 8W 1 50PPM 4 00158 407 Resistor Metal Film 1 8W 1 50PPM 4 00409 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00409 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00746 407 Resistor Metal Film 1 8W 1 50PPM 4 00317 407 Resistor Metal Film 1 8W 1 50PPM 4 00652 407 Resistor Metal Film 1 8W 1 50PPM 4 00409 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00409 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00523 407 Resistor Metal Film 1 8W 1 50PPM 4 00158 407 Resistor Metal Film 1 8W 1 50PPM 4 00193 407 Resistor Metal Film 1 8W 1 50PPM 4 00136 407 Resistor Metal Film 1 8W 1 50PPM 4 00654 407 Resistor Metal Film 1 8W 1 50PP
50. Interface The GPIB IEEE 488 interface is provided by U1202 a TMS9914A controller U1203 and U1204 buffer data I O to the GPIB connector U1202 is programmed to provide an interrupt to the processor whenever there is bus activity addressed to the unit RS232 Interface The SCN2641 UART U1303 provides all of the UART functions including baud rate generation Standard baud rates up to 19 2k can be generated from the 3 6864 MHz clock U1305 buffers the outgoing data and control signals Incoming signals are received by U1304 The RS232 port is a DCE and may be connected to a PC using a standard serial cable not a null modem cable Expansion Connector Service Guide The 120 pin connector carries all of the necessary interconnections to the System backplane Power is also delivered through this connector Peripherals on this board are accessed whenever PCS1 from the CPU is active U1401 and U1402 provide on board decoding SR780 Network Signal Analyzer 2 10 Circuit Description Power Supply Board This section covers schematics MPWR 1 through MPWR 2 in Chapter 5 Caution Dangerous voltages are present on this circuit board whenever the instrument is M attached to an AC power source and the rear panel power switch is ON Always disconnect the power cord and wait at least one minute before opening the unit Check the LED at the top edge of the power supply board The unit is safe only if the LED is OFF If the LED is ON th
51. L 32 PIN 600 MIL TEST JACK TEST JACK 80C186 20 7TAACTOA 40 000 MHZ 74ACT573 74ACT573 74ACT573 7TAACT245 TAACT245 TAACT245 TAACT245 74ACT573 T4ACT245 TAACT245 TAACT32 74ACT08 SR780 U213 SR780 U214 TAACT32 128KX8 70 128KX8 70 128KX8 70 128KX8 70 74ALS138 74ALS138 74AC74 7ALS148 74HC573 74HC21 74HC164 T4HCT 74 74HC595 74HC573 74HC574 74HC573 74HC273 T4HCT 74 T4HCT 74 74HC 14 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Vertical Test Jack Vertical Test Jack Integrated Circuit Surface Mount Pkg Integrated Circuit Thru hole Pkg Crystal Oscillator Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg GAL PAL I C GAL PAL I C Integrated Circuit Thru hole Pkg STATIC RAM I C STATIC RAM I C STATIC RAM I C STATIC RAM I C Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thr
52. M 4 00356 407 Resistor Metal Film 1 8W 1 50PPM 4 00057 401 Resistor Carbon Film 1 4W 5 4 00233 424 Resistor Carbon Comp 2W 5 4 00031 401 Resistor Carbon Film 1 4W 596 4 00479 407 Resistor Metal Film 1 8W 1 50PPM 4 00457 407 Resistor Metal Film 1 8W 1 50PPM 4 00138 407 Resistor Metal Film 1 8W 1 50PPM 4 00161 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00066 401 Resistor Carbon Film 1 4W 5 4 00210 407 Resistor Metal Film 1 8W 1 50PPM 4 00193 407 Resistor Metal Film 1 8W 1 50PPM 4 00107 402 Resistor Carbon Comp 1 2W 5 4 00107 402 Resistor Carbon Comp 1 2W 5 4 00080 401 Resistor Carbon Film 1 4W 596 4 00080 401 Resistor Carbon Film 1 4W 5 4 00045 401 Resistor Carbon Film 1 4W 596 4 00022 401 Resistor Carbon Film 1 4W 596 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00032 401 Resistor Carbon Film 1 4W 5 4 00034 401 Resistor Carbon Film 1 4W 596 4 00045 401 Resistor Carbon Film 1 4W 596 4 00062 401 Resistor Carbon Film 1 4W 5 4 00034 401 Resistor Carbon Film 1 4W 596 4 00022 401 Resistor Carbon Film 1 4W 596 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00241 407 Resistor Metal Film 1 8W 1 50PPM 4 00048 401 Resistor Carbon Film 1 4W 596 4 00188 407 Resistor Metal Film 1 8W 1 50PPM 4 00161 407 Resistor Metal Film 1 8W 1 50PPM 4 00188 407 Resistor Metal Film 1 8W 1 50PPM 4 00188 407
53. Network Signal Analyzer 1 14 Performance Tests 3 Amplitude accuracy is verified at 1 0 kHz and various input ranges For each range setting in the table below perform steps 3a through 3d Input Range pk AC Calibrator Amplitude 46 dBV 2 509 mVrms 38 dBV 6 302 mVrms 30 dBV 15 830 mVrms 14 dBV 99 881 mVrms 4 dBV 0 7934 Vrms 10 dBV 1 5830 Vrms 22 dBV 6 3021 Vrms 34 dBV 25 089 Vrms a Set the AC calibrator to the amplitude shown in the table b Press Input Chl Input Range Enter the range from the table Ch2 Input Range Enter the range from the table C Press Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max d Record the marker Y reading for both displays for each range 4 Frequency response is checked at frequencies above 1 kHz The test frequencies are listed below The measurements are performed for two different input ranges Test Frequencies 24 kHz 48 kHz 72 kHz 96 kHz a Set the AC calibrator to 1 0 kHz and an amplitude of 99 881 mVrms b Set the frequency synthesizer to 1 0 kHz C Press Frequency Center Frequency 1 Select KHz Enter SR780 Network Signal Analyzer Performance Tests Input Chl Input Range gt 1 4 Enter lt Ch2 Input Range gt 1 4 Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max The Y value of the markers should bot
54. PO Monolitic Ceramic 50v 5 Ra Cap NPO Monolitic Ceramic 50v 5 Ra Capacitor Tantalum 35V 20 Rad Capacitor Electrolytic 50V 20 Rad Capacitor Electrolytic 50V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Electrolytic 50V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad SR780 Network Signal Analyzer 4 26 Parts List RefNo SRS Part No Value Component Description 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00023 529 1U Cap Monolythic Ceram
55. SR780 Network Signal Analyzer Service Guide Service 3 13 10 If the supplies are not correct try one or both of the following A Follow procedure A1 to replace the power supply board and repeat this check B Remove one or more of the other boards and recheck the power supply This assumes that the supply voltage is being affected by a bad board elsewhere in the unit The Digital power drives the CPU Video IO Disk cards and the CRT assembly The ANLG and CH1 power drives the Chl analog input board The ANLG and CH2 power drives the Ch2 analog input board The DIG power drives the DSP board If removing a board fixes the supply voltage then proceed to replace the suspect board or assembly If nothing seems to help contact Stanford Research Systems or an authorized representative Service Procedure B1 Replacing the CRT l Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Release the CRT connector cable from the System backplane behind the CRT enclosure The CRT enclosure is secured by four screws two on the left and two on the right These screws are in slots in the enclosure Remove these screws Slide the CRT enclosure back until the front clears the front panel bezel Lift the enclosure up and ou
56. Service Guide Model SR780 Network Signal Analyzer S RS Stanford Research Systems 1290 D Reamwood Avenue Sunnyvale CA 94089 U S A Phone 408 744 9040 Fax 408 744 9049 Email info thinkSRS com www thinkSRS com Copyright O 1995 Stanford Research Systems Inc All Rights Reserved Revision 2 3 February 2005 Certification Stanford Research Systems certifies that this product met its published specifications at the time of shipment Stanford Research Systems further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology NIST Warranty This Stanford Research Systems product is warranted against defects in materials and workmanship for a period of one 1 year from the date of shipment Service For warranty service or repair this product must be returned to a Stanford Research Systems authorized service facility Contact Stanford Research Systems or an authorized representative before returning this product for repair Information in this document is subject to change without notice Copyright Stanford Research Systems Inc 1995 All rights reserved Stanford Research Systems Inc 1290 D Reamwood Avenue Sunnyvale California 94089 Printed in U S A SR780 Network Signal Analyzer Service Guide Safety and Preparation For Use WARNING Dangerous voltages capable of causing injury or death are present in this instrument Use extreme
57. V 10 SL 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00262 548 01U
58. V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX SR780 Network Signal Analyzer Service Guide Parts List 4 17 Ref No SRS Part No Value Component Description 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 548 1U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00225 54
59. ackplane Board Parts List This section covers schematics MBKPL 20 through MBKPL 23 in Chapter 5 System Backplane Parts List RefNo SRS Part No Component Description 5 00023 529 1U 5 00023 529 1U 5 00023 529 1U 1 00240 108 96 PIN RT ANGLE 1 00237 108 120 PIN VERTICA 1 00016 160 RS232 25 PIN D 1 00272 130 34 PIN DI 0 001 12 053 1 3 4 24R 0 001 12 053 1 3 4 24R 1 00237 108 120 PIN VERTICA 1 00238 161 GPIB SHIELDED 1 00016 160 RS232 25 PIN D 1 00242 130 20 PIN ELH VERT 1 00237 108 120 PIN VERTICA 1 00119 116 3 PIN WHITE 1 00272 130 34 PIN DI 1 00152 116 11 PIN WHITE 1 00250 116 2 PIN WHITE 7 00524 701 SR780 MOTHER 4 00772 402 33 0 00043 011 4 40 KEP 0 00187 021 4 40X1 4PP 0 00390 024 1 72X1 4 0 00391 010 1 72X5 32X3 64 0 00415 031 4 40X1 2 M F 6 00076 600 2 SPKR Service Guide Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U DIN Connector Female DIN Connector Female Connector D Sub Right Angle PC Female Connector Male Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin DIN Connector Female Connector IEEE488 Reverse R A Female Connector D Sub Right Angle PC Female Connector Male DIN Connector Female Header Amp MTA 156 Connector Male Header Amp MTA 156 Header Amp MTA 156 Printed Circuit Board Resistor Carbon Comp 1 2W 5 Nut Kep Screw Panhead Phillips Screw Slotted Nut Hex
60. all of the computations related to the measurement before it is displayed on the screen This includes digital heterodyning frequency shifting digital filtering and downsampling Fast Fourier Transforming averaging and output display processing scaling magnitude calc log sqrt etc These functions are implemented within a system comprised of four functional blocks the Digital Signal Processor DSP the Timing Generator the I O Interface and the Trigger Input The fifth functional block is the Source Generator The source is synthesized filtered and attenuated before being passed to the output connector Digital Signal Processor The SR780 utilizes a single ADSP21020 digital signal processor clocked at 33 MHz All instructions are completed in a single 30 ns cycle The ADSP21020 has two external data buses Data Memory DM and Program Memory PM There is no internal memory Program memory is 128k x 48 and Data memory is 128k x 40 The memory is mounted on two SIMM modules Each SIMM module contains 128k words of 20 ns 128k x 8 memory IC s In addition a 2M x 32 DRAM module is located on the DM bus This module may be upgraded to 4M or 8M x 32 PAL U301 provides simple DRAM refresh and control functions Accesses to the DRAM are always multi cycle The DRAM is used for capture waterfall and trace storage These functions do not require fast multiple memory accesses Communication between the DSP and the host CPU 80C186 is handl
61. amic COG 1 5 00148 545 1000P 50V Capacitor Monolythic Ceramic COG 1 5 00148 545 1000P 50V Capacitor Monolythic Ceramic COG 1 5 00148 545 1000P 50V Capacitor Monolythic Ceramic COG 1 5 00148 545 1000P 50V Capacitor Monolythic Ceramic COG 1 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00148 545 1000P 50V Capacitor Monolythic Ceramic COG 1 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00219 529 01U Cap Monolythic Ceramic 50V 20 Z5U 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00003 501 10P Capacitor Ceramic Disc 50V 10 SL 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00053 512 033U Cap Stacked Metal Film 50V 5 40 85c 5 00052 512 01U Cap Stacked Metal Film 50V 5 40 85c 5 00050 566 0033U Cap Polyester Film 50V 5 40 85c Rad 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic C
62. ard MKEY 1 DSP Board D780 1 through D780 9 Analog Input Boards A780 1 through A780 7 Analyzer Backplane M780 1 through M780 4 Service Guide SR780 Network Signal Analyzer 3 10 Service Service Procedures Caution Potentially lethal voltages are present in this instrument This unit is to be M serviced by qualified service personnel only There are no user serviceable parts inside Check the red LED at the top edge of Power Supply board The unit is safe only if the LED is OFF If the LED is ON then voltages are present within the unit USE CAUTION Use caution when checking circuits with the power on Always disconnect the power cord before replacing or servicing any component inside the chassis Required Equipment 1 DC AC Voltmeter DVM 5 1 2 digit accuracy True RMS AC to 100 kHz Recommended Fluke 8840A with Option 09 or equivalent Frequency Synthesizer function generator 1 Hz to 100 kHz 0 2 dB amplitude accuracy Recommended SRS DS335 or equivalent Philips screwdrivers various sizes Slot head screwdrivers various sizes Hex keys various sizes Oscilloscope 10 MHz bandwidth or greater Service Procedure A1 Power Supply Board Replacement I Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling
63. assemblies Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Crystal Crystal Hardware Misc SR780 Network Signal Analyzer 4 10 Parts List Power Supply Board Parts List This section covers schematics MPRW 1 through MPRW 2 in Chapter 5 RefNo SRS Part No Value Component Description 5 00134 529 100P Cap Monolythic Ceramic 50V 2096 Z5U 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U 5 00022 501 001U Capacitor Ceramic Disc 50V 1096 SL 5 00134 529 100P Cap Monolythic Ceramic 50V 2096 Z5U 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U 5 00022 501 001U Capacitor Ceramic Disc 50V 1096 SL 5 00124 526 5600U Capacitor Electrolytic 35V 2096 Rad 5 00124 526 5600U Capacitor Electrolytic 35V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00124 526 5600U Capacitor Electrolytic 35V 2096 Rad 5 00124 526 5600U Capacitor Electrolytic 35V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00127 524 2 2U Capacitor Tantalum 50V 2096 Rad 5 00041 509 220U Capacitor Electrolytic 50V 2096 Rad 5 00127 5
64. blem continues proceed with the proper service procedures Always reset the instrument after performing any service The only field service which may be performed is at the board and assembly level If the DSP board or either Analog Input board is replaced with factory calibrated replacement boards the unit will remain calibrated If individual components are replaced on a board the calibration is not guaranteed Individual component replacement on the DSP or Analog boards is not recommended SR780 Network Signal Analyzer 3 4 Service Troubleshooting Table Symptoms Procedure Cd Screen is blank when e Does the unit beep when front panel keys are pressed power is turned on Yes see Display Problems After reset is there a signal at the Source Output Yes see Display Problems Proceed to Service Procedure A2 Power Supply Check If the Power Supply is OK see Display Problems Display Problems Is the screen brightness turned down Press the Brighter button at the lower right of the screen below the softkeys Is the display unstable Yes proceed to Service Procedure B2 CRT Check Is the display blank Yes proceed to Service Procedure B2 CRT Check e If there still a problem proceed to Service Procedure D3 Video IO Board Replacement Keypad not functioning e Is there a key stuck in the down position Yes release the stuck key e Proceed to Service Procedure C1 Keypad Check Knob not fu
65. board by using the card ejectors to release the board and pull the board up and out Use the DVM to verify that the Source Output BNC center conductor and shield are connected to the front most SMB jack at the bottom of the card cage directly behind the Source Output The BNC center conductor connects to the female center of the SMB jack The BNC shield connects to the SMB shield If the connection is OK follow Procedure F1 to replace the DSP board Otherwise contact SRS for more information Service Procedure F7 DSP Memory Module Replacement Service Guide 1 N Before replacing a memory module reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 3 2 to locate the DSP board in the Analyzer card cage nearest the CRT Remove the card cage cover by loosening the five screws in the cover Remove the DSP board by using the card ejectors to release the board and pull the board up and out There are three memory SIMM modules on the DSP board They are t
66. caution whenever the instrument cover is removed Do not remove the cover while the unit is plugged into a live outlet Caution This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR set for the wrong AC line voltage or if the wrong fuse is installed Line Voltage Selection The SR780 operates from a 100V 120V 220V or 240V nominal AC power source having a line frequency of 50 or 60 Hz Before connecting the power cord to a power source verify that the LINE VOLTAGE SELECTOR card located in the rear panel fuse holder is set so that the correct AC input voltage value is visible Conversion to other AC input voltages requires a change in the fuse holder voltage card position and fuse value Disconnect the power cord open the fuse holder cover door and rotate the fuse pull lever to remove the fuse Remove the small printed circuit board and select the operating voltage by orienting the printed circuit board so that the desired voltage is visible when pushed firmly into its slot Rotate the fuse pull lever back into its normal position and insert the correct fuse into the fuse holder Line Fuse Verify that the correct line fuse is installed before connecting the line cord For 100V 120V use a 1 5 Amp fuse For 220V 240V use a 3 4 Amp fuse Line Cord The SR780 has a detachable three wire power cord for connection to the power source and to a protective ground The exposed metal parts of the instrument are connected to the ou
67. d by diodes D601 and D6302 N601 divides the trigger signal and trigger level by two to accommodate the input range of the comparator C604 provides high frequency hysteresis when the output latch cannot respond fast enough and U601B and U602A provide low frequency hysteresis R603 and N601A determine the level of hysteresis The DC trigger level is set by the 8 bit DAC U607A U606 buffers and shifts the DAC output The Trig In signal is latched in PAL U703 which synchronizes the trigger to the A D clocks and interrupts the DSP Source Generator The source is output by DAC U501 AD766 Since the DAC is clocked synchronously with the A D converters the source is synchronous with the input sampling The output of U501 is buffered by U502 AD744 U505 U507 form an elliptic anti aliasing filter to remove high frequency components K501 selects the anti aliasing filter output or the pink noise filter output U530 as the source U509A is used as an 8 bit attenuator and U510 is a divide by 10 or 100 attenuator U512 1s a high current output buffer which provides the low output impedance Interface To CPU The CPU interface provides the communication pathway between the DSP board and the main CPU board All signal interconnections are made via the 120 pin connector J902 U801 U803 are buffers for the address and data bus connections These buffer chips are Service Guide SR780 Network Signal Analyzer 2 14 Circuit Description enabled only when t
68. e Analog Input board is configured by the DSP board via its serial I O Interface U601 U603 form a 24 bit shift register and latch Data is shifted in serially from the DSP board and latched to internal latches The outputs of the latches are used to control relays switches etc During normal operation this interface is static and no random digital noise is present on this board SR780 Network Signal Analyzer Service Guide Circuit Description 2 17 U606 is a serial EEPROM containing the calibrations for the amplifier and anti aliasing filter U606 is read by the host CPU 80C186 via a port on the DSP board This EEPROM is only read at power on and does not contribute digital noise to this board Power Several voltages are generated on the Analog Input board locally 15 V is generated for most of the analog IC s U531 U532 A dedicated 15 V supply is also generated for the front end amplifier U501 U502 5 V is generated for the A D Converter U521 U522 as well as a digital 5 V for the digital I O U690 Analog 6 V is generated for the analog switches U541 U542 12V is provided for the relays U551 U511 provides the high voltage bias for the ICP supply The 20 VDC supply which is the source of most of the power supplies is not grounded at the power supply It is grounded by the Analog Input board to reduce ground loops at the analog inputs Thus the 20 VDC floats when no Analog Input boards are present If eith
69. e keypad and knob are attached to the Disk card by a ribbon cable This cable attaches next to the Keyboard connector below the CRT The cable attaches to the back of the keypad board on the front panel Make sure that the cable is firmly attached at both ends and that the cable is not damaged Check that the ground wire 1s attached firmly to the chassis and to the keypad board Push the Disk card inward to make sure that it is seated properly The keypad signals are carried to the System backplane via this card Replace the front panel bezel being careful to engage the slots which secure the front of the Disk card Replace the eight bezel screws Replace the handle and the pivot screws SR780 Network Signal Analyzer Service Guide 12 13 Service 3 15 If the keypad still does not function then the problem may be on the CPU board The keypad circuit board contains no active circuitry and the rubber keys are very unlikely to fail To replace the CPU board follow Procedure D1 CPU Board Replacement Replace the top lid and refasten the eight lid screws Service Procedure C2 Knob Check Service Guide 1 t 10 11 12 13 Perform the Knob check in the System lt Diagnostics gt menu Verify knob rotation and direction If the test passes then the knob is OK If the test fails or cannot be completed then proceed Turn the power OFF Remove the power cord from the power entry module Remove the eight b
70. e keys are not in a menu since they are used frequently and within any menu The FUNCTION keys perform common functions such as Auto Scale and Auto Range These keys can be accessed at any time lt Softkeys gt Knob Reset The SR780 has a menu driven user interface The Menu keys each display a menu of softkeys The softkeys are at the right of the video display and have different functions depending upon the displayed menu Softkeys are referenced in brackets like lt Span gt or lt Units gt There are three types of softkeys buttons lists and numeric values A button performs a function such as lt Full Span gt A list presents a list of choices or options in the entry field at the top of the screen Use the knob to make a selection and press Enter lt Measurement gt is an example of a list A numeric value presents the current value in the entry field and awaits numeric entry Enter a new value with the entry keys and press Enter lt Start Freq gt is an example of a numeric value The knob normally moves the markers within the displays If a parameter has been highlighted by its softkey the knob adjusts the parameter List parameters are most easily modified with the knob Numeric parameters may also be adjusted with the knob Knob list selections are referenced in parenthesis like Hanning Throughout this section it will be necessary to reset the analyzer into a known default state To do this press System to
71. ed through FIFO memories U302 U304 These are 25 ns 4k x 9 FIFO s U302 and U303 provide a 16 bit wide data path from the DSP to the host CPU This allows data to flow to the host for display as fast as possible U304 provides an 8 bit data path from the host CPU to the DSP for commands and data The FIFO s allow the sender and the receiver to run at their full rates without waiting for the other The DSP can interrupt the host by raising the 186INTO line output from port U710 and latching the request in U720A The host clears the interrupt by writing to address INTO CLR decoder U805 The host CPU can interrupt the DSP via IRQO and IRQI by writing to ports in U805 These interrupts are generally used by the sender to signal that a FIFO is full and the receiver should read the FIFO Timing Signal Generator The timing signal generator provides all timing signals for the A D and D A Converters and their corresponding serial ports The master clock is chosen from either U705 30 208 Mhz or U706 30 933 Mhz U706 is used if the FFT Base Frequency is 102 4 kHz and U705 is used if the FFT Base Frequency is 100 0 kHz U701 U703 implement a 118 state 7 bit counter The state machine generates the convert clocks frame sync and bit clocks for the converters U716 re synchronizes the clock signals and drives the off SR780 Network Signal Analyzer Service Guide Circuit Description 2 13 board signals to the Analyzer backplane U712 latches the
72. ee Fig 3 3 9 Press Input Chl Input Range lt Ch2 Input Range 2 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 70 dBV remember 60 dBV is greater than 70 dBV and 80 dBV is less than 70 dBV then proceed to the next step If the reading is greater than 70 dBV adjust the High Gain Offset pot to minimize the marker reading see Fig 3 3 10 Press Input Chl Input Range lt Ch2 Input Range 5 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 85 dBV remember 80 dBV is greater than 85 dBV and 90 dBV is less than 85 dBV then proceed to the next step If the reading is greater than 85 dBV adjust the High Gain Offset pot to minimize the marker reading see Fig 3 3 11 Press SR780 Network Signal Analyzer Service Guide Service Guide 12 13 Service 3 25 Input Chl Input Range lt Ch2 Input Range gt 0 Enter Auto Scale A Auto Scale B If the marker reading is less than 50 dBV remember 40 dBV is greater than 50 dBV and 60 dBV is less than 50 dBV then proceed to the next step If the reading is greater than 50 dBV adjust the Low Gain Offset pot to minimize the marker reading see Fig 3 3 Connect the Source Output to both the Ch1 A and B inputs Ch2 A and B Use equal length cables from A and B to a BNC TEE Connect the cable from the Source Output to the TEE Press Source Sine
73. en DO NOT attempt any service on the unit Removing the Power Supply Never remove or replace this board when the power cord is attached The Power Supply Board is held in by two rear panel screws which hold the power supply shield to the chassis These screws prevent accidental removal of this board The unit should never be operated without these screws in place Power Supply Connector The 120 pin connector carries all of the necessary interconnections to the System backplane Switch AC and the transformer secondaries are carried by this connector The supply outputs to the System and Analyzer backplanes is also carried by this connector For safety this board cannot be inserted backwards Test Points The test points along the top edge of the board are provided for supply testing while the instrument is powered ON These test points are current limited for safety Always measure the supply voltages relative to the correct ground test point as labeled on the board System Power The system power for the System backplane CPU Video IO disk drive and CRT is provided by the switching power supply module mounted on the Power Supply board This switcher is inside the power supply shield The switcher accepts AC line input and generates 5V 5V 12V and 12V The 5V powers all of the system logic CPU and Video IO as well as the DSP logic 12V powers the CRT and the fans Analog Power Analog power to the Analyzer backplane is generated
74. er Analog Input board is present then this supply is grounded Service Guide SR780 Network Signal Analyzer 2 18 Circuit Description SR780 Network Signal Analyzer Service Guide 3 1 Chapter 3 Service This chapter provides a troubleshooting guide with service procedures to debug and repair this unit at a board or assembly level In This Chapter 3 3 Before Proceeding With Service Warranty Service CAUTION Reset Calibration Troubleshooting Table Circuit Board Locations System Components Analyzer Components Schematic Diagram Locations Service Procedures Caution Required Equipment Service Procedure Al Power Supply Board Replacement Service Procedure A2 Power Supply Check Service Procedure B1 Replacing the CRT Service Procedure B2 CRT Check Service Procedure C1 Keypad Check Service Procedure C2 Knob Check Service Procedure D1 CPU Board Replacement Service Procedure D2 Battery Check Service Procedure D3 Video IO Board Replacement Service Procedure F1 DSP Board Replacement Service Procedure F2 Analog Board Replacement Service Procedure F3 Checking the Analog Inputs Service Procedure F4 Checking the Amplitude Service Procedure F5 Checking the Trigger Service Procedure F6 Checking the Source Service Procedure F7 DSP Memory Module Replacement Service Procedure G1 Replacing the Disk Drive Service Procedure J1 Adjusting the DC Offset and CMR Service Guide 3 3 3 3 3 3 3 3
75. eramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 5 00034 526 100U Capacitor Electrolytic 35V 2096 Rad 5 00034 526 100U Capacitor Electrolytic 35V 2096 Rad 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U Service Guide SR780 Network Signal Analyzer 4 16 Parts List RefNo SRS Part No Value Component Description 5 00023 529 1U Cap Monolythic Ceramic 50V 2096 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00016 501 470P Capacitor Ceramic Disc 50V 10 SL 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL 5 00013 501 33P Capacitor Ceramic Disc 50V 10 SL 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad 5 00093 517 15U Capacitor Tantalum 35V 2096 Rad 5 000
76. eset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 3 2 to locate the Analog boards in the Analyzer card cage behind the input BNC connectors Remove the card cage cover by loosening the five screws in the cover The Channel 1 Analog board is in the center of the card cage The Channel 2 Analog board is on the right Pull off the small shield at the front using the finger hole Remove the correct Analog board by using the card ejectors to release the board and pull the board up and out Use the DVM to verify that the A input BNC center conductor and shield are connected to the front most SMB jack at the bottom of the card cage directly behind the inputs The BNC center conductor connects to the female center of the SMB jack The BNC shield connects to the SMB shield Use the DVM to verify that the B input BNC connects properly to the rear most SMB jack If both connections are OK proceed to Procedure F2 to replace the Analog board Otherwise contact SRS for more i
77. esistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp 1 2W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp 1 2W 5 Resistor Carbon Comp 1 2W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Socket THRU HOLE Socket THRU HOLE Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack Vertical Test Jack SR780 Network Signal Analyzer 4 32 Parts List Analog Input Board Parts List RefNo SRS Part No Component Description 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 3 00246 340 3 008 17 340 3 00461 340 3 00461 340 3 00423 34
78. esistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 0 1 25ppm Service Guide Parts List 4 29 RefNo SRS PartNo Value Component Description 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00467 407 Resistor Metal Film 1 8W 1 50PPM 4 00698 407 Resistor Metal Film 1 8W 1 50PPM 4 00582 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00159 407 Resistor Metal Film 1 8W 1 50PPM 4 00429 407 Resistor Metal Film 1 8W 1 50PPM 4 00136 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00137 407 Resistor Metal Film 1 8W 1 50PPM 4 00583 407 Resistor Metal Fi
79. ested cable Check that the SR780 is set to output data to the GPIB interface NOT the RS232 interface The output interface is set in the System lt Remote gt menu Check the instrument GPIB address The address is set in the System lt Remote gt menu Proceed to Service Procedure D3 Video IO Board Replacement Printer problems Check that the printer cable is attached securely to the Printer port on the rear panel NOT the RS232 port Use a tested cable Check the Printer Type selected in the Output menu The SR780 can output to Epson compatible dot matrix printers or HP LaserJet InkJet compatible laser printers Make sure that the printer is On Line and has paper Proceed to Service Procedure D1 CPU Board Replacement SR780 Network Signal Analyzer Service Guide Service 3 7 Symptoms Procedure Unit displays an active e Apply a known 10 kHz 0 5 Vrms sine wave to the A baseline spectrum but no input of the non functioning channel Does the signal signal appear in the spectrum No proceed to Service Procedure F3 Checking the Analog Inputs Does the unit pass the DSP memory checks Use System lt Show Version gt to review the power on test results No see DSP memory check fails Does the unit pass the Analog board memory checks Use System lt Show Version gt to review the power on test results No see Analog memory check fails No data graphed in the Does the unit pass the DSP memory check
80. ezel screws Replace the handle and the pivot screws Replace the top lid and refasten the eight lid screws Replace the power cord Reset the unit by turning the power ON while holding down the backspace key Run the Disk test in the System lt Diagnostics gt menu SR780 Network Signal Analyzer Service Guide Service 3 23 Service Procedure J1 Adjusting the DC Offset and CMR 1 6 Service Guide The DC Offset and CMR adjustments affect each other and must be done together This procedure requires a 50Q terminator A small but long slotted screwdriver is required to adjust the potentiometers Reset the unit by turning the power ON while holding down the backspace key Let it warm up for at least an hour The adjustment procedure for the two channels is the same The procedure described below uses Channel 1 as the example To adjust Channel 2 press Active Display to switch to DisplayB Spectrum of Ch2 and when necessary adjust the Ch2 input parameters in the Input menu and make the input connections to the Ch2 A and B inputs Press Auto Scale B instead of Auto Scale A when necessary Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the card cage cover by loosening the five screws which secure it The adjustment pots on the Analog board are towards the front Remove t
81. h read 17 0 dB 0 15 dB d Set the AC calibrator and frequency synthesizer to the frequency in the table e Press Frequency Center Freq gt Enter the signal frequency Start Reset Wait for the average to settle Link Marker Max f Record the marker Y reading for both displays Repeat steps 4d and 4e for all of the frequencies listed 5 Now repeat the frequency response measurements at a different input range a Set the AC calibrator to 1 kHz and an amplitude of 6 3021 Vrms b Set the frequency synthesizer to 1 kHz C Press Freq Center Freq gt 1 lt kHz gt Input Chl Input Range gt 2 2 Enter lt Ch2 Input Range 2 2 Enter Start Reset Wait for the average to finish Auto Scale A SR780 Network Signal Analyzer 1 16 Performance Tests Auto Scale B Link Marker Max The Y value of the marker should now read 19 0 dB 0 15 dB d Repeat steps 4d through 4f above 6 This completes the amplitude accuracy and frequency response test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer Performance Tests 1 17 5 Amplitude Linearity This test measures the amplitude linearity This tests how accurately the analyzer measures a signal smaller than full scale Setup We will use the frequency synthesizer to provide an accurate frequency and the AC calibrator to provide a sine wave with an exact amp
82. h the plastic knob on the outside Pry off the front cover of the plastic knob with a small screwdriver or your fingertips The cover is the plastic disk with the dimple in it Remove the plastic knob by loosening the nut which holds the plastic knob onto the digital pot s shaft Remove the mounting nut at the base of the shaft Once this nut is removed the pot can be removed from the bezel Pull the pot free while leaving the cable attached Move the cable from the old pot to the new pot maintaining the correct cable orientation SR780 Network Signal Analyzer 3 16 Service 14 15 16 17 18 Place the new pot shaft into the hole in the bezel and secure the shaft with the mounting nut Replace the plastic knob on the shaft and tighten the nut at the center Replace the knob cover Replace the front panel bezel being careful to engage the slots which secure the front of the Disk card Replace the eight bezel screws Replace the handle and the pivot screws If the knob still does not function then the problem may be on the CPU board The keypad circuit board contains no active circuitry and is very unlikely to fail To replace the CPU board follow Procedure D1 CPU Board Replacement Replace the top lid and refasten the eight lid screws Service Procedure D1 CPU Board Replacement 1 m 8 9 10 Before replacing the CPU board reset the unit by turning the power OFF and ON while holding down the back
83. he Trigger Input as well Verify that the signal appears in the top spectrum do not change any settings In the Trigger menu set the Trigger Mode to Auto Arm Set the Trigger Source to External and verify that the Trig indicator in the display turns on If the unit does not trigger proceed to step 4 External TTL Trigger check Reset the unit by holding down the backspace key while turning the power ON Use the function generator to apply a known 10 kHz 0 5 Vrms sine wave to the Chl A input Use a BNC cable to connect the function generator TTL SYNC output to the Trigger Input as well Verify that the signal appears in the top spectrum do not change any settings In the Trigger menu set the Trigger Mode to Auto Arm Set the Trigger Source to Ext TTL and verify that the Trig indicator in the display turns on If the unit does not trigger proceed to step 4 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 3 2 to locate the DSP board in the Analyzer card cage closest to the CRT Remove the card cage cover by loosening the five screws in the cover Remove the DSP board by using the
84. he CPU board is writing to the DSP board This is signaled by PCS4 from the 80C186 This helps isolate the activity on the CPU board from affecting circuitry on the DSP board U808 and U809 are simple latches used to hold configuration data for the DSP board U805 is a decoder which generates the chip selects and strobes needed by the DSP board U810 is a serial EEPROM which holds the calibration data required by the source and trigger circuits SR780 Network Signal Analyzer Service Guide Circuit Description 2 15 Analog Input Boards This section covers schematics A780 1 through A780 7 in Chapter 5 The Analog Input boards provide the very important link between the user s input signal and the DSP processor From the front panel BNC the user s signal passes through a low distortion front end amplifier gain stages attenuators anti aliasing filter and finally an A D Converter Once converted to digital form the input signal is ready to be processed by the DSP The two inputs use identical Analog Input boards The routing on the Analyzer backplane keeps them separate Input Amplifier The goal of any measurement instrument is to perform some given measurement while affecting the quantities to be measured as little as possible As such the input amplifier is often the most critical stage in the entire signal path The design of the front end input amplifier in the SR780 was driven by an effort to provide optimum performance in the follow
85. he DRAM Data Memory and Program Memory The Data and Program modules are SRS custom parts and must be replaced with SRS supplied parts The standard DRAM buffer is a 2Mx32 70ns or faster 72 pin SIMM The DRAM upgrades are 4Mx32 and 8Mx32 70ns or faster 72 pin SIMM s The DRAM module must have its identification pin s grounded in order to work in the SR780 These pins are standard in all modules but may not be connected in modules not supplied by SRS Check the data sheet for the module to ensure that the correct ID pins are connected To remove a memory module simply release the spring latches at each end of the socket Insert the new module making sure that the notch end is correctly positioned Make sure that the spring latches are engaged around the edge of the board SR780 Network Signal Analyzer 3 22 Service 10 11 12 13 Replace the DSP board making sure to align the board edges with the plastic card guides Make sure that the board is aligned with the connectors and jacks at the bottom of the card cage before pressing the board into place Do not press the board in if the jacks at the front are not engaged properly These jacks are easily damaged Make sure that the board is seated completely in its socket Replace the card cage cover and tighten the cover screws Replace the top lid and refasten the eight lid screws Reset the unit by turning the power ON while holding down the backspace key Service Procedu
86. he board is OFF before proceeding SR780 Network Signal Analyzer Service Guide Service 3 17 See Figure 3 1 to locate the CPU board it s next to the Power Supply board Use the DVM to measure the battery voltage at the BATT test point at the top of the board There are two test points BATT is the one towards the rear The battery voltage should be at least 2 7V relative to the chassis If the battery voltage is low then proceed to replace the battery Release the bar which secures the boards in place Remove the CPU board by using the card ejectors to release the board and pull the board up and out Desolder the two battery pins Cut the plastic tie which secures the battery and remove the battery Insert a new battery check the polarity solder the two pins Secure the battery with a new tie if available Replace the CPU board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Reset the unit by turning the power ON while holding down the backspace key If the unit continues to have battery problems then follow Procedure D1 to replace the CPU board Service Procedure D3 Video IO Board Replacement 1 N 8 9 Before replacing the Video IO board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the po
87. he front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 3 2 to locate the Analog boards in the Analyzer card cage behind the input BNC connectors Remove the card cage cover by loosening the five screws in the cover The Channel 1 Analog board is in the center of the card cage The Channel 2 Analog board is on the right Pull off the small shield at the front using the finger hole Remove the correct Analog board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides Make sure that the board is aligned with the connectors and jacks at the bottom of the card cage before pressing the board into place Do not press the board in if the jacks at the front are not engaged properly These jacks are easily damaged Make sure that the board is seated completely in its socket SR780 Network Signal Analyzer Service Guide 8 9 Service 3 19 Replace the small shield at the front Replace the card cage cover and tighten the cover screws Replace the top lid and refasten the eight lid screws 10 Reset the unit by turning the power ON while holding down the backspace key Service Procedure F3 Checking the Analog Inputs 1 N Before proceeding r
88. he small shield cover at the front of the Analog board Simply pull the shield up using the finger hole The five adjustment pots are shown in Figure 3 3 Do not make any other adjustments Output Offset Analog Board High Gain CMR High Gain Offset Low Gain Offset Low Gain CMR Figure 3 3 Analog Adjustments Press the following keys to clear the internal offset calibrations and turn Auto Offset Off System Diagnostics Kill AutoOff gt SR780 Network Signal Analyzer 3 24 Service 7 Press the following keys to set the input configuration and frequency span Input Chl Input Range lt Ch2 Input Range gt 0 Enter Chl Grounding gt lt Ch2 Grounding gt Select Ground Enter Chl Coupling lt Ch1 Coupling Select DC Enter Freq Span 1 6 Select KHz Enter Start Freq gt 0 Enter Marker Width Link Select Spot Enter 8 Connect a 50Q termination to the Chl Ch2 A input This shorts the input to ground so the analyzer s own DC offset is measured Rotate the knob so that the marker is at 0 Hz The marker positions display above the graph should read 0 Hz The marker amplitude is the DC offset If the marker reading is less than 50 dBV remember 40 dBV is greater than 50 dBV and 60 dBV is less than 50 dBV then proceed to the next step If the reading is greater than 50 dBV adjust the Output Offset pot to minimize the marker reading s
89. ic 50V 2096 Z5U 5 00100 517 2 2U Capacitor Tantalum 35V 2096 Rad 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00457 301 1N5241B Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 3 00004 301 1N4148 Diode 1 00241 141 RT ANGLE JACK SMB Connector 1 00241 141 RT ANGLE JACK SMB Connector 1 00234 109 96 PIN RT ANGLE DIN Connector Male 3 00240 335 BS 211 DC12 GF Relay 3 00240 335 BS 211 DC12 GF Relay 3 00239 335 HS 212 12 Relay 3 00239 335 HS 212 12 Relay 3 00239 335 HS 212 12 Relay 3 00239 335 HS 212 12 Relay 3 00240 335 BS 211 DC12 GF Relay 3 00239 335 HS 212 12 Relay 3 00240 335 BS 211 DC12 GF Relay 3 00240 335 BS 211 DC12 GF Relay 3 00240 335 BS 211 DC12 GF Relay 3 00240 335 BS 211 DC12 GF Relay 3 00240 335 BS 211 DC12 GF Relay 4 00244 421 10KX4 Res Network SIP 1 4W 2 Isolated 4 00690 421 3 3KX4 Res Network SIP 1 4W 2 Isolated 4 00252 425 100X5 Resistor Network SIP 1 4W 2 Common 4 00252 425 100X5 Resistor Network SIP 1 4W 2 Common 4 00252 425 100X5 Resistor Network SIP 1 4W 2 Common SR780 Network Signal Analyzer Service Guide Parts List 4 27 RefNo SRS PartNo Value Component Description 4 00252 425 100X5 Resistor Network SIP 1 4W
90. ing This is the Ch2 CMRR in dB at 1 kHz 7 This completes the CMRR measurement test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer Performance Tests 1 13 4 Amplitude Accuracy and Flatness This test measures the input amplitude accuracy and frequency response Setup We will use the frequency synthesizer to provide an accurate frequency and the AC calibrator to provide a sine wave with an exact amplitude Connect the output of the frequency synthesizer to the phase lock input of the calibrator Connect the output of the AC calibrator to the Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required Set the Synthesizer to Set the AC Calibrator to Function Sine Frequency 1 0 kHz Frequency 1 0 kHz Amplitude 0 707 mVrms Amplitude 0 5 Vrms Voltage Off Offset off or OV Phase Lock On Sweep off Sense Internal Modulation none Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Window Window Select Flattop Enter Freq Span 1 6 Select KHz Enter Center Freq gt 1 Select KHz Enter Input Chl Coupling Select AC Enter lt Ch2 Coupling Select AC Enter Average lt Averaging Type Select Linear Enter lt Avgs gt 1 0 Enter lt Averaging gt Select On Enter SR780
91. ing areas input voltage noise input current noise input capacitance harmonic distortion and common mode rejection CMR To provide such performance an FET differential input amplifier with common mode feedback architecture was chosen The input signal is first passed through a series of relays to select input mode K102 input coupling K104 and input attenuation K105 K108 Relay K101 provides shield grounding Relay K106 switches in the ICP current supply The 30 dB input attenuator formed by resistors R103 R106 serves to attenuate very large signals as well as providing protection to the input FET in the presence of very high voltages gt 50 Vpk To prevent damage to the input FET the input voltage is monitored by comparators U106 and U107 High voltages cause the input attenuator to be automatically engaged regardless of the user gain setting at the front panel Resistors R107 and R108 provide some input protection to the input FET with only a slight penalty in input voltage noise The input FET U100 is an extremely low noise matched pair of FET s with a voltage input noise of approximately 3 5 nV VHz To improve distortion performance the input FET s are cascoded to maintain a constant drain source voltage across each FET This prevents modulation of the drain source voltage by the input voltage U104 senses the source voltage and maintains the same voltage at the drain with some DC offset determined by resistors N102 and N103 U1
92. inputs This shorts the inputs so the analyzer s own DC offset will be measured Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Freq lt Span gt 1 6 select kHz Enter Marker lt Marker gt Select Link Enter Use the knob to move the markers to 0 Hz Average lt Averaging Type gt Select Linear Enter lt Avgs gt 1 0 Enter lt Averaging gt Select On Enter 3 a Press Input Chl Input Range gt 3 0 Enter lt Ch2 Input Range gt 3 0 Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B b Record the marker Y values for both displays on the 30 dBV range C Press Chl Input Range gt 5 0 Enter SR780 Network Signal Analyzer 1 10 Performance Tests lt Ch2 Input Range gt 5 0 Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B d Record the marker Y values for both displays for the 50 dBV range 4 This completes the DC measurement test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer Performance Tests 1 11 3 Common Mode Rejection This test measures the common mode rejection of the analyzer inputs Setup We will use the frequency synthesizer to provide the signal Connect the frequency synthesizer out
93. it Thru hole Pkg 3 00055 340 74LS74 Integrated Circuit Thru hole Pkg 3 00055 340 74LS74 Integrated Circuit Thru hole Pkg 3 00195 340 CA3082 Integrated Circuit Thru hole Pkg 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg 3 00387 340 74HC245 Integrated Circuit Thru hole Pkg 3 00387 340 74HC245 Integrated Circuit Thru hole Pkg 3 00036 340 74HCOO Integrated Circuit Thru hole Pkg 3 00037 340 74HC138 Integrated Circuit Thru hole Pkg 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg 3 00440 340 74HC573 Integrated Circuit Thru hole Pkg 3 00411 340 74HC273 Integrated Circuit Thru hole Pkg 3 0041 1 340 74HC273 Integrated Circuit Thru hole Pkg 3 00604 342 2KX8 SERIAL EPROM PROM I C 3 001 14 329 7815 Voltage Reg TO 220 TAB Package 3 00120 329 7915 Voltage Reg TO 220 TAB Package 0 00012 007 TO 220 Heat Sinks 0 00043 011 4 40 KEP Nut Kep 0 00209 021 4 40X3 8PP Screw Panhead Phillips 0 00231 043 1 32 4 SHOULD Washer nylon 0 00243 003 TO 220 Insulators 0 00341 010 2 56 HEX Nut Hex 0 00373 000 CARD EJECTOR Hardware Misc Service Guide SR780 Network Signal Analyzer 4 22 Parts List DSP Board Parts List RefNo SRS Part No Component Description 0 00728 021 2 56X1 2PP Screw Panhead Phillips SR780 Network Signal Analyzer Service Guide Parts List 4 23 Analog Input Board Parts List This section covers schematics A780 1 through A780 7 in Chapter 5 The SR780 uses two of these boards
94. kage 3 00096 340 LM317L Integrated Circuit Thru hole Pkg 3 00100 340 LM337L Integrated Circuit Thru hole Pkg 3 00346 329 7812 Voltage Reg TO 220 TAB Package 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg 3 00064 340 CA3081 Integrated Circuit Thru hole Pkg 3 00049 340 74HC74 Integrated Circuit Thru hole Pkg 3 00604 342 2KX8 SERIAL EPROM PROM I C 3 00694 343 SR780 U607 GAL PAL I C 3 00155 340 74HC04 Integrated Circuit Thru hole Pkg 3 00037 340 74HC138 Integrated Circuit Thru hole Pkg 3 00265 340 74HC595 Integrated Circuit Thru hole Pkg 3 00343 340 7TAALS32 Integrated Circuit Thru hole Pkg 3 00116 325 78L05 Transistor TO 92 Package 0 00012 007 TO 220 Heat Sinks 0 00043 01 1 4 40 KEP Nut Kep 0 00209 021 4 40X3 8PP Screw Panhead Phillips 0 00231 043 1 32 4 SHOULD Washer nylon 0 00243 003 TO 220 Insulators 0 00373 000 CARD EJECTOR Hardware Misc 0 00516 042 BNC Washer lock Service Guide SR780 Network Signal Analyzer 4 34 Parts List Analyzer Backplane Board Parts List This section covers schematics M780 1 through M780 4 in Chapter 5 Analyzer Backplane Parts List RefNo SRS Part No Component Description 5 00219 529 5 00219 529 5 00134 529 5 00219 529 5 00219 529 5 00134 529 5 00219 529 5 00219 529 5 00134 529 5 00219 529 5 00219 529 5 00134 529 5 00219 529 5 00219 529 5 00134 5
95. l DispB Ch2 19 20 dBV 4 20 dBV 13 80 dBV 29 80 dBV 45 80 dBV Upper Limit 160 144 kHz Frequency Accuracy Input Frequency Lower Limit 96 000 kHz Phase Accuracy Frequency Trigger Source 95 9976 kHz Lower Limit Upper Limit DispA Chl 96 0024 kHz DispB Ch2 lt 90 dB Upper Limit 10 24 kHz Chl Noise and Spurious Signals Noise floor Start Frequency 93 0 deg Span 512 Hz 51 2 kHz Spurious signals Center Frequency 51 2 kHz 51 2 kHz Span 230 Hz 500 Hz 1 kHz 5 kHz 10 kHz 25 kHz 50 kHz 75 kHz 101 kHz 400 Hz 400 Hz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz DispA Chl DispB Ch2 87 0 deg Upper Limit 160 dBVrms NHz 160 dBVrms NHz DispA Chl DispB Ch2 Upper Limit 135 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk 140 dBVpk SR780 Network Signal Analyzer 1 34 Performance Tests SR780 Performance Test Record Page 3 of 3 10 Sine Source Amplitude Frequency Level Lower Limit Upper Limit 1 kHz 1000 mV 0 3 dBV 0 3 dBV 1 kHz 100 mV 20 3 dBV 19 7 dBV 1 kHz 10 mV 40 3 dBV 39 7 dBV Amplitude Flatness Frequency Level Lower Limit Upper Limit 20 48 kHz 1000 mV 0 3 dBV 0 3 dBV 40 96 kHz 1000 mV 0 3 dBV 0 3 dBV 61 44 kHz 1000 mV 0 3 dBV 0 3 dBV 81 92 kHz 1000 mV 0 3 dBV 0 3 dBV 99 072 kH
96. l fuse holder is set so that the correct AC input voltage value is visible Conversion to other AC input voltages requires a change in the fuse holder voltage card position and fuse value Disconnect the power cord open the fuse holder cover door and rotate the fuse pull lever to remove the fuse Remove the small printed circuit board and select the operating voltage by orienting the printed circuit board so that the desired voltage is visible when pushed firmly into its slot Rotate the fuse pull lever back into its normal position and insert the correct fuse into the fuse holder Verify that the correct fuse is installed For 100V 120V use a 1 5 A fuse For 220V 240V use a 3 4 A fuse Use the DVM to verify that the fuse is not blown or damaged Disconnect the power cord Use the DVM to check that the GND test point on the Power Supply board is connected to the chassis and also to the ground pin of the power entry module The GND test point is at the top edge of the board directly behind the notch If GND is not shorted to chassis or power ground check the GND green wires on the rear panel chassis ground connection above the power switch on the inside One green wire connects directly to the power entry module ground the other to the System backplane via the AC power connector Do not continue if there is a fault in the chassis or power grounds SR780 Network Signal Analyzer 3 12 Service 7 Connect the power cord and turn the po
97. lack screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the two hex screws which connect the handle arms to the chassis Remove the handle by pulling the arms apart slightly Remove the eight screws which secure the front panel bezel to the chassis These screws are exposed when the lid is removed There are two screws along each side and the top and bottom Remove the front panel bezel by pulling it slowly off towards the front The knob is attached to the bezel There is a ground wire and cable extending from the keypad back to the main chassis The knob is connected by a 5 wire ribbon cable to the keypad assembly Check that the cable is secure at both ends The keypad and knob are attached to the Disk card by a ribbon cable This cable attaches next to the Keyboard connector below the CRT The cable attaches to the back of the keypad board on the front panel Make sure that the cable is firmly attached at both ends and that the cable is not damaged Check that the ground wire 1s attached firmly to the chassis and to the keypad board Push the Disk card inward to make sure that it is seated properly The knob signals are carried to the System backplane via this card If the knob still fails to function proceed to replace the digital pot The digital pot 1s secured to the front panel bezel by a nut underneat
98. litude Connect the output of the frequency synthesizer to the phase lock input of the calibrator Connect the output of the AC calibrator to the Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required Set the Synthesizer to Set the AC Calibrator to Function Sine Frequency 1 0 kHz Frequency 1 0 kHz Amplitude 6 3021 Vrms Amplitude 0 5 Vrms Voltage Off Offset off or OV Phase Lock On Sweep off Sense Internal Modulation none Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Window lt Window gt Select Flattop Enter Freq lt Span gt 1 6 Select kHz Enter lt Center Freq gt 1 Select kHz Enter Input Chl Coupling Select AC Enter lt Ch2 Coupling Select AC Enter Chl Input Range gt 2 2 Enter lt Ch2 Input Range 2 2 Enter SR780 Network Signal Analyzer 1 18 Performance Tests Average lt Averaging Type gt Select Linear Enter lt Avgs gt 1 0 Enter lt Averaging gt Select On Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max 3 For each of the amplitudes listed below perform steps 3a through 3c AC Calibrator Amplitudes 6 3021 Vrms 1 1207 Vrms 141 09 mVrms 22 361 mVrms 3 544 mVrms a Set the AC calibrator to the amplitude in the table b P
99. lm 1 8W 1 50PPM 4 00699 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00200 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00188 407 Resistor Metal Film 1 8W 1 50PPM 4 00031 401 Resistor Carbon Film 1 4W 596 4 00577 407 Resistor Metal Film 1 8W 1 50PPM 4 00130 407 Resistor Metal Film 1 8W 1 50PPM 4 00034 401 Resistor Carbon Film 1 4W 596 4 00448 407 Resistor Metal Film 1 8W 1 50PPM 4 00448 407 Resistor Metal Film 1 8W 1 50PPM 4 00739 407 Resistor Metal Film 1 8W 196 50PPM 4 00894 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 196 25ppm 4 00237 407 Resistor Metal Film 1 8W 196 50PPM 4 00280 407 Resistor Metal Film 1 8W 196 50PPM 4 00895 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 196 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 196 25ppm 4 00186 407 Resistor Metal Film 1 8W 1 50PPM 4 00308 407 Resistor Metal Film 1 8W 1 50PPM 4 00444 407 Resistor Metal Film 1 8W 1 50PPM 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00748 408 Resistor Metal Film 1 8W 0 1 25ppm 4 00178 407 Resistor Metal Film 1 8W 1 50PPM 4 00200 407 Resistor Metal Film 1 8W
100. lt Preset gt and then Enter to confirm This sets the source to sine output at 10 24 kHz and 500 mVpk amplitude 2 Press the keys in the following sequence Input Chl Input Range gt 4 Enter lt Ch2 Input Range gt 4 Enter Auto Scale A Auto Scale B Average lt Avgs gt 2 5 Enter lt Averaging Mode gt Select Vector Enter lt Averaging gt Select On Enter Marker lt Mode gt Link Select Harmonic Enter lt Harmonics gt Link 5 Enter Link Marker Max 3 Record the THD reading for DisplayA from the THD menu box 4 Press Active Display Make DisplayB the active display 5 Record the THD reading for DisplayB from the THD menu box 6 This completes the harmonic distortion test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer 1 32 Performance Tests SR780 Performance Test Record Serial Number Firmware Revision Equipment Used Tested By Date Page 1 of 3 1 Self Tests Test Power On Test Keypad Knob System RAM System ROM Video RAM Help ROM 2 DC Offset 3 Common Mode Rejection Input Range DispA Chl DispB Ch2 Upper Limit 30 dBV 50 dBV 80 dBV 80 dBV Input Range 2 dBV Frequency 1 0 kHz 4 Amplitude Accuracy and Flatness Input Range Calibrator Ampl Lower Limit DispA Chl DispA Chl DispB
101. memories are mapped into the upper 32k of I O space One of the sixteen 32k banks is selected by BA15 BA18 set in the system status port This keeps ROM data from using up program memory space Keypad Interface The keypad is organized as 8 columns and 8 rows of switch closures The conductive rubber keys provide the switch closures U607 strobes the columns and U606 detects the switch closure The diodes D601 D608 prevent one column from affecting another All of the outputs from U607 are set high and U606 is read periodically by the processor As long as 00H is read no key is pressed and the strobes are left on When a non zero value is read then the key strobes are activated individually in order to decode which key is down Spin Knob The knob is an optical encoder buffered by U612 Each transition of its quadrature outputs is clocked into U610 or U611 and generates an interrupt at the output of U507B The processor keeps track of the knob s direction and speed Keyboard Interface The PC keyboard interface uses U603 to convert serial data from the keyboard into a parallel byte for the processor to read The data format from the keyboard is a leading start bit followed by 8 data bits U603 is reset by a processor read When a key is pressed the bits are shifted into U603 When the start bit appears at the QH output 7 bits of the data byte are in U603 U601 is the 9th bit of the shift register When U601 clocks in the start bit U601 must have
102. n Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Me
103. nce Tests 1 1 The performance tests described in this section are designed to verify with a high degree of confidence that the unit is performing within the specifications The results of each test should be recorded on the test sheet at the end of this section In This Chapter Getting Ready oN Oo A WO N Hardkeys lt Softkeys gt Knob Reset Serial Number Firmware Revision Necessary Equipment Warm Up The Test Record If A Test Fails Self Tests DC Offset Common Mode Rejection Amplitude Accuracy and Flatness Amplitude Linearity Anti alias Filter Attenuation Frequency Accuracy Phase Accuracy 9 Noise and Spurious Signals 10 Sine Source 11 Harmonic Distortion SR780 Performance Test Record SR780 Network Signal Analyzer 1 2 Performance Tests SR780 Network Signal Analyzer Performance Tests 1 3 Getting Ready Hardkeys The keypad consists of four groups of hardkeys keys with printed labels Hardkeys are referenced in braces like Active Display or Input The ENTRY keys are used to enter numeric parameters which have been highlighted by a soft key The MENU keys select a menu of soft keys Pressing a menu key will change the menu boxes which are displayed next to the soft keys Each menu presents a group of similar or related parameters and functions The CONTROL keys start and stop data acquisition toggle the active display and link parameters and functions Thes
104. nctioning e Proceed to Service Procedure C2 Knob Check System lt Diagnostics gt e Proceed to Service Procedure D1 CPU Board System RAM check fails Replacement System lt Diagnostics gt e Contact SRS for replacement ROM components If System ROM check or failure continues proceed to Service Procedure D1 CPU Help ROM check fails Board Replacement System lt Diagnostics gt e Proceed to Service Procedure D3 Video IO Board Video RAM check fails Replacement Unit does not recall e Proceed to Service Procedure D2 Battery Check settings at power on Clock does not keep e Proceed to Service Procedure D2 Battery Check time correctly SR780 Network Signal Analyzer Service Guide Service 3 5 Symptoms Procedure Power On DSP memory e If Data Memory fails proceed to Service Procedure F7 check fails Replacing DSP Memory Modules e If Program Memory fails proceed to Service Procedure Use System lt Show F7 Replacing DSP Memory Modules Version gt to review test results e If DRAM Errors are detected proceed to Service Procedure F7 Replacing DSP Memory Modules e Ifthe DSP Cal ROM is not OK proceed to Service Procedure F1 DSP Board Replacement e Proceed to Service Procedure F1 DSP Board Replacement e Proceed to Service Procedure F6 Checking the Source DSP memory upgrade e To upgrade the DSP DRAM to 4M or 8M proceed to Service Procedure F7 Replacing DSP Memory Modules P
105. nd disk drive tests are not required but should be periodically checked See the System menu for more information about those tests Setup No external setup is required for this test Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm During re boot the DSP memory and calibration tests should all be OK To review this power on screen use System Show Version 2 Press the keys in the following sequence System Diagnostics Keypad Test gt Press all of the front panel keys until all of the boxes are filled in Then press any key to exit this screen Knob Test gt Rotate the knob to verify rotation and direction lt Return gt lt Memory gt System RAM lt Begin gt All of the system memory chips should Pass lt Return gt System ROM Begin All of the system memory chips should Pass Return Video RAM gt lt Begin gt All of the video memory chips should Pass lt Return gt SR780 Network Signal Analyzer 1 8 Performance Tests lt Help ROM gt lt Begin gt All of the memory chips should Pass lt Return gt lt Return gt 3 This completes the functional hardware tests Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer Performance Tests 1 9 2 DC Offset This test measures the DC offset of the input Setup Connect a 50Q feedthrough termination to the Chl A and Ch2 A
106. nformation Service Procedure F4 Checking the Amplitude 1 Check the amplitude accuracy by following the procedure outlined in Performance Test 4 Amplitude Accuracy and Flatness in Chapter 6 of the SR780 Operating Manual If the test passes then check the signal source in question If the test fails follow Procedure F2 to replace an Analog board Service Procedure F5 Checking the Trigger 1 Service Guide Internal Trigger check Reset the unit by holding down the backspace key while turning the power ON Use the function generator to apply a known 10 kHz 0 5 Vrms sine wave to both A inputs Verify that the signal appears in both spectra do not change any settings In the Trigger menu set the Trigger Mode to Auto Arm Set the Trigger Source to Chl and verify that the Trig indicator in the display turns on Set the Trigger Source to Ch2 and verify that the Trig indicator turns on If SR780 Network Signal Analyzer 3 20 Service neither trigger source works follow Procedure F1 to replace the DSP board If one of the internal sources fails the problem is probably with the Analog board for that channel Follow Procedure F2 to replace the Analog board If both trigger sources are OK continue External Trigger check Reset the unit by holding down the backspace key while turning the power ON Use the function generator to apply a known 10 kHz 0 5 Vrms sine wave to the Ch1 A input Use a BNC cable to connect the signal to t
107. nnects to the system backplane via two short cables at the center of the chassis just behind the CRT Figure 2 2 Analyzer Components Chassis Top View DSP Board Chl Analog Input Board Ch2 Analog Input Board Analyzer Backplane Front Both the system and the analyzer backplanes are passive and contain no active circuitry They only provide power distribution signal routing between the various boards and to external ports or devices Schematic Diagram Locations Schematic diagrams are located in Chapter 5 Board Assembly Schematic s see Chapter 10 CPU Board MCPU 1 through MCPU 9 Video IO Board MVID 10 through MVID 14 Power Supply MPWR 1 through MPWR 2 System Backplane MBKPL 20 through MBKPL 23 Disk Card MBKPL 24 Keypad Board MKEY 1 DSP Board D780 1 through D780 9 Analog Input Boards A780 1 through A780 7 Analyzer Backplane M780 1 through M780 4 SR780 Network Signal Analyzer Service Guide Circuit Description 2 5 CPU Board This section covers schematics MCPU 1 through MCPU 9 in Chapter 5 The CPU board contains the main microprocessor system CPU memory front panel and printer interfaces are on this board Two off board data buses are also driven from this board The I O Expansion data bus connects the CPU board with the Video IO and Aux slots on the System backplane The External data bus connects to the DSP Board via the Analyzer backplane Microprocessor System The microprocessor U101 is
108. o 102 0 kHz SR780 Network Signal Analyzer 1 20 Performance Tests 4 Measure the anti alias filter attenuation Press Input lt More gt Chl AA Filter gt Select On Enter Ch2 AA Filter gt Select On Enter Start Reset Wait for the average to finish Record the marker Y readings for both displays 5 This completes the anti alias filter attenuation test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer Performance Tests 1 21 7 Frequency Accuracy This test measures the frequency accuracy of the analyzer This tests the accuracy of the fundamental crystal timebase inside the unit Setup We will use the frequency synthesizer to provide the signal Connect the output of the frequency synthesizer to the Chl A input of the analyzer Be sure to use the appropriate terminations where required Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 96 000 kHz and an amplitude of 500 mVrms 3 Press the keys in the following sequence Freq lt Span gt 2 0 0 Select Hz Enter lt Center Freq gt 9 6 Select kHz Enter Auto Scale A Marker Max 4 Wait for the spectrum to settle at least 5 seconds then record the marker frequency reading for DisplayA 5 This completes the frequency accuracy test Enter the results of this test in the
109. ode gt Select Vector Enter lt Averaging Type gt Select Linear Enter lt Averaging gt Select On Enter 4 Record the marker Y readings for both displays Make sure that the marker frequency is 10 24 kHz 5 This completes the phase accuracy test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer Performance Tests 1 25 9 Noise and Spurious Signals This test measures the analyzer noise floor and checks for spurious signals Setup Connect 50Q feedthrough terminations to the Chl A and Ch2 A inputs This grounds the inputs so the analyzer s input noise is measured Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Press the keys in the following sequence Freq lt Span gt 5 1 2 Select kHz Enter lt Start Freq gt 5 1 2 Select Hz Enter Window lt Window gt Select Hanning Enter Input Chl Input Range gt 5 0 Enter lt Ch2 Input Range gt 5 0 Enter Chl Coupling Select AC Enter lt Ch2 Coupling Select AC Enter Chl Grounding gt Select Ground Enter lt Ch2 Grounding gt Select Ground Enter Display Options lt PSD Units gt Link Select On Enter Display Setup lt Units gt Link Select dBVrms VHz Enter lt Y max gt Link 1 0 0 Enter SR780 Network Signal Analyzer 1 26 Perfo
110. ork SIP 1 4W 2 Isolated Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network DIP 1 4W 2 8 Ind Res Network SIP 1 4W 2 Isolated Res Network SIP 1 4W 2 Isolated Printed Circuit Board Transistor TO 92 Package Transistor TO 92 Package Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Service Guide Parts List 4 5 CPU Board Parts List RefNo SRS Part No Component Description 4 00021 401 4 00054 401 1 00108 150 1 00156 150 1 00156 150 1 00156 150 1 00156 150 1 00156 150 1 00156 150 1 00156 150 1 00156 150 1 00143 101 1 00143 101 3 00595 360 3 00591 340 6 00147 621 3 00585 340 3 00585 340 3 00585 340 3 00586 340 3 00586 340 3 00586 340 3 00586 340 3 00585 340 3 00586 340 3 00586 340 3 00587 340 3 00588 340 3 00693 343 3 00692 343 3 00587 340 3 00551 341 3 00551 341 3 00551 341 3 00551 341 3 00342 340 3 00342 340 3 00274 340 3 00347 340 3 00440 340 3 00043 340 3 00303 340 3 00467 340 3 00265 340 3 00440 340 3 00454 340 3 00440 340 3 00411 340 3 00467 340 3 00467 340 3 00039 340 Service Guide 1 0K 200K PLCC 68 TH 32 PIN 600 MIL 32 PIN 600 MIL 32 PIN 600 MIL 32 PIN 600 MIL 32 PIN 600 MIL 32 PIN 600 MIL 32 PIN 600 MI
111. ower On Analog e Ifthe Chl or Ch2 Analog Cal ROM is not OK proceed memory check fails to Service Procedure F2 Analog Board Replacement Use System lt Show Version to review test results Disk Drive problems e Check that your disk is DS DD or DS HD Try a new disk e Check that the disk write protect tab is closed e Perform the disk drive test in the System lt Diagnostics gt menu e Proceed to Service Procedure G1 Disk Drive Replacement e If there is still a problem proceed to Service Procedure D3 Video IO Board Replacement Service Guide SR780 Network Signal Analyzer 3 6 Service Symptoms Procedure RS232 problems e Check that the RS232 cable is attached securely to the RS232 port on the rear panel NOT to the Printer port Use a tested cable Check that the SR780 is set to output data to the RS232 interface NOT the GPIB interface The output interface is set in the System cRemote menu Check the RS232 setup in the System lt Remote gt menu Make sure that the proper baud rate word length and parity is selected Place a loop back connector on the RS232 port A loop back connector is a male DB25 connector with pins 2 and 3 connected together Perform the RS232 test in the System lt Diagnostics gt menu If the test fails proceed to Service Procedure D3 Video IO Board Replacement GPIB problems Check that the GPIB cable is securely fastened to the rear panel GPIB port Use a t
112. peat this procedure one more time Otherwise follow Procedure F2 to replace the Analog board SR780 Network Signal Analyzer Service Guide 4 1 Chapter 4 Parts Lists This chapter lists the components on the major circuit assemblies in the SR780 The schematics for each board are shown in Chapter 5 In This Chapter CPU Board Parts List Video IO Board Parts List Power Supply Board Parts List System Backplane Parts List Disk Card Parts List DSP Board Parts List Analog Input Board Parts List Analyzer Backplane Parts List Miscellaneous and Chassis Assembly Parts List Service Guide 4 3 4 7 4 10 4 13 4 14 4 15 4 23 4 34 4 35 SR780 Network Signal Analyzer 4 2 Parts Lists SR780 Network Signal Analyzer Service Guide Parts Lists 4 3 CPU Board Parts List This section covers schematics MCPU 1 through MCPU 9 in Chapter 5 RefNo SRS PartNo Value Component Description 6 00001 612 BR 2 3A 2PIN PC Battery 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00262 548 01U AXIAL Capacitor Ceramic 50V 80 20 Z5U AX 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL 5 00064 513 0047U Capacitor Mylar Poly 50V 5 Rad 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL 5 00012 501 330P Capacitor Ceramic Disc 50V 10 SL 5 00022 501 001U Capacitor Ceramic Disc 50
113. ply Board Replacement 3 10 Power Supply Check 3 11 CRT Replacement 3 13 CRT Check 3 14 Keypad Check 3 14 Knob Check 3 15 CPU Board Replacement 3 16 Battery Check 3 17 Video IO Board Replacement 3 17 DSP Board Replacement 3 18 Analog Board Replacement 3 18 Service Guide SR780 Network Signal Analyzer iv Contents Checking the Analog Inputs Checking the Amplitude Checking the Trigger Checking the Source DSP Memory Module Replacement Replacing the Disk Drive Adjusting the DC Offset and CMR Chapter 4 Parts List CPU Board Video IO Board Power Supply Board System Backplane Disk Card DSP Board Analog Input Board Analyzer Backplane Miscellaneous and Chassis Assembly Parts List Chapter 5 Schematic Diagrams Schematic Diagram List CPU Board Video IO Board Power Supply Board System Backplane Disk Card Keypad Board DSP Board Analog Input Board Analyzer Backplane Demo Filter SR780 Network Signal Analyzer 3 19 3 20 3 20 3 21 3 21 3 22 3 24 4 3 4 7 4 10 4 13 4 14 4 15 4 23 4 34 4 35 5 1 MCPU 1 MVID 1 MPWR 1 MBKPL 1 MBKPL 24 MKEY 1 D780 1 A780 1 M780 1 F780 1 Service Guide Table of Figures Service Guide Figure 2 1 System Components Figure 2 2 Analyzer Components Figure 3 1 System Components Figure 3 2 Analyzer Components Figure 3 3 Analog Adjustments SR780 Network Signal Analyzer vi SR780 Network Signal Analyzer Service Guide Chapter 1 Performa
114. put to both the Chl A and Chl B inputs of the analyzer Use equal length cables from A and B to a BNC TEE Connect the cable from the synthesizer output to the TEE Procedure 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 1 kHz and an amplitude of 500 mVrms 3 Setup the measurement Press the keys in the following sequence Freq lt Span gt 1 6 Select KHz Enter Center Freq gt 1 Select KHz Enter Input Chl Input Range gt 2 Enter Average lt Averaging Type Select Linear Enter lt Avgs gt 1 0 Enter lt Averaging gt Select On Enter Wait for the average to finish Auto Scale A Marker Max Marker Ref Input Chl Input Mode gt Select A B Enter Start Reset Wait for the average to finish 4 Record the marker Y reading This is the Chl CMRR in dB at 1 kHz SR780 Network Signal Analyzer 1 12 Performance Tests 5 Move the input cables from Ch1 A and B to Ch2 A and B Repeat the measurement for Ch2 Press the keys in the following sequence Active Display Make DisplayB the active display Input Ch2 Input Range 2 Enter Start Reset Wait for the average to finish Auto Scale B Marker Max Marker Ref Input Ch2 Input Mode gt Select A B Enter Start Reset Wait for the average to finish 6 Record the marker Y read
115. quency are attenuated by at least 96 dB This is accomplished with an 8 zero 9 pole elliptical low pass filter U230 U233 The pass band of this filter is DC to 102 4 kHz with a ripple of 0 5 dB The stopband begins at 156 kHz Stopband attenuation is nominally 100 dB U234A follows the anti aliasing filter to sum the DC offset correction from DAC U361 with the signal A second 51 2 kHz anti aliasing filter U240 U243 is used for two channel octave measurements Relays K202 K203 and K204 select an anti aliasing filter or bypasses the filters altogether The filter output is buffered by U244A and U244B to the trigger circuit on the DSP board A Weighting Filter The A Weighting filter is constructed with a standard implementation using U310A and U310B Relay K301 selects the filter U317 is a dual amplifier which splits the signal into two paths inverted and non inverted Each signal path drives one of the A D channels Comparator U391 detects overload based upon the A D converter reference voltage AID Converter The A D Converter converts the inverted and non inverted signals to two digital data streams Conversion takes place at a rate of 262 144 samples per second FFT Base 102 4 kHz A Burr Brown PCM1750 dual 18 bit A D converter is used for this purpose U402A and U402D drive the data signals to the Analyzer backplane and to the DSP board Timing signals for the A D Converter are received via U402B and U402C I O Interface Th
116. rated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Transistor TO 92 Package Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Transistor TO 92 Package Service Guide Parts List 4 33 Ref No SRS Part No Value Component Description 3 00124 325 79L15 Transistor TO 92 Package 3 00096 340 LM317L Integrated Circuit Thru hole Pkg 3 00116 325 78L05 Transistor TO 92 Package 3 00122 325 79L05 Transistor TO 92 Package 3 001 14 329 7815 Voltage Reg TO 220 TAB Package 3 00120 329 7915 Voltage Reg TO 220 TAB Pac
117. rdware Misc Hardware Misc Screw Sheet Metal Wire 18 UL1015 Strip 3 8 x 3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Termination Standoff Screw Allen Head Connector Amp MTA 156 Connector Male Cable Assembly Ribbon Connector Amp MTA 156 Connector Male Cable Assembly Ribbon Cable Assembly Ribbon Connector Amp MTA 156 Cable Assembly Ribbon Cable Assembly Ribbon SOFTPOT Switch Rocker STATIC RAM I C Varistor Zinc Oxide Nonlinear Resistor Cap Ceramic 50V SMT 1206 10 X7R Cap Tantalum SMT all case sizes Fuse Transformer Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Machined Part Machined Part Fabricated Part Service Guide Parts List 4 37 Miscellaneous and Chassis Assembly Parts List RefNo SRS Part No Component Description 7 00554 720 7 00555 720 7 00621 720 7 00622 709 7 00623 720 7 00624 720 7 00625 720 7 00627 740 7 00628 701 7 00630 701 7 00632 735 7 00662 714 7 00673 721 7 00674 721 7 00675 721 7 00723 720 8 00045 840 9 00267 917 9 008 15 924 0 00187 021 0 00195 020 3 00599 350 3 00613 350 7 00405 720 7 00542 720 7 00543 720 7 00548 720 7 00620 720 7 00631 720 Service Guide SR780 21 SR780 23 9 CRT SCREEN SR780 SR780 30 SR780 31 32 SR780 7 SR780 33 34 MEGA KEYPAD SR780
118. re G1 Replacing the Disk Drive 10 11 12 13 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the two hex screws which connect the handle arms to the chassis Remove the handle by pulling the arms apart slightly Remove the eight screws which secure the front panel bezel to the chassis These screws are exposed when the lid is removed There are two screws along each side and the top and bottom Remove the front panel bezel by pulling it slowly off towards the front The keypad is attached to the bezel There is a ground wire and cable extending from the keypad back to the main chassis The keypad and knob are attached to the Disk card by a ribbon cable This cable attaches next to the Keyboard connector below the CRT Note the cable orientation and remove the cable from the Disk card Pull the Disk card straight out to remove it Insert the new Disk card Make sure that the card is in the plastic card guides under the CRT Do not force the card in if the card is not in the guides Push the card in until the connector is secure Reattach the keypad cable to the Disk card Replace the front panel bezel being careful to engage the slots which secure the front of the Disk card Replace the eight b
119. ress Start Reset and wait for the average to finish c Record the marker Y reading for both displays 4 This completes the amplitude linearity test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer We will use the frequency synthesizer to provide the signal 3 Press the keys in the following sequence Freq lt Span gt 8 0 0 Select Hz Enter lt Center Freq gt 1 0 2 Select kHz Enter Input More Chl AA Filter Select Off Enter Ch2 AA Filter Select Off Enter Average lt Averaging Type Select Linear Enter lt Avgs gt 1 0 Enter lt Averaging gt Select On Enter Start Reset Wait for the average to finish Auto Scale A Auto Scale B Link Marker Max Link Marker Ref Performance Tests 1 19 6 Anti alias Filter Attenuation This test measures the attenuation of the anti alias filters This tests how well the analyzer rejects frequencies outside the 102 4 kHz frequency range Connect the output of the frequency synthesizer to the Chl A and Ch2 A inputs of the analyzer Be sure to use the appropriate terminations where required 1 Reset the unit by pressing System lt Preset gt and then Enter to confirm 2 Set the frequency synthesizer to a frequency of 160 144 kHz and an amplitude of 500 mVrms This references the un filtered out of band signal at 160 144 kHz aliased t
120. rmance Tests Average lt Avgs gt 2 0 Enter lt Averaging Type gt Select Linear Enter lt Averaging gt Select On Enter Marker lt Width gt Link Select Wide Enter lt Seeks gt Link Select Mean Enter Start Reset Wait for the average to finish Link Marker Max 3 Record the marker Y readings for both displays 4 Press Freq lt Start Freq gt 5 1 2 Select KHz Enter Start Reset Wait for the average to finish Link Marker Max 5 Record the marker Y readings for both displays 6 Press Display Options lt PSD Units Select Off Enter Display Setup Units Select dBVpk Enter Marker Seeks Select Max Enter 7 For each of the spans listed below perform steps 7a through 7c SR780 Network Signal Analyzer Center Frequency 230 Hz 500 Hz 1 kHz 5 kHz 10 kHz 25 kHz 50 kHz 75 kHz 101 kHz a Press Freq lt Span gt Enter the span from the table lt Center Freq gt Enter the center frequency from the table b Wait for the average to finish 20 averages Link Marker Max c Record the marker Y readings for both displays Span 400 Hz 400 Hz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz 1 6 kHz Performance Tests 1 27 8 This completes the noise and spurious signal test Enter the results of this test in the test record at the end of this section SR780 Network Signal Analyzer 1 28
121. ront and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding See Figure 3 2 to locate the DSP board in the Analyzer card cage nearest the CRT Remove the card cage cover by loosening the five screws in the cover Remove the DSP board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides Make sure that the board is aligned with the connectors and jacks at the bottom of the card cage before pressing the board into place Do not press the board in if the jacks at the front are not engaged properly These jacks are easily damaged Make sure that the board is seated completely in its socket Replace the card cage cover and tighten the cover screws Replace the top lid and refasten the eight lid screws 10 Reset the unit by turning the power ON while holding down the backspace key Service Procedure F2 Analog Board Replacement 1 N Before replacing an Analog board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at t
122. s Use displays System lt Show Version gt to review the power on test results No see DSP memory check fails Proceed to Service Procedure D1 CPU Board Replacement Input problems Apply a known 10 kHz 0 5 Vrms sine wave to the A coupling grounding or input of the non functioning channel Does the signal input range appear in the spectrum No proceed to Service Procedure F3 Checking the Analog Inputs Proceed to Service Procedure F2 Analog Board Replacement Measured amplitude of e Proceed to Service Procedure F4 Amplitude Check signal not correct Unit does not trigger or e Proceed to Service Procedure F5 Trigger Check trigger is unstable when in triggered mode Large DC offset on e Proceed to Service Procedure J1 Adjusting DC Offset spectrum and CMR Common Mode e Proceed to Service Procedure J1 Adjusting DC Offset Rejection problem and CMR Service Guide SR780 Network Signal Analyzer 3 8 Service Circuit Board Locations The SR780 s circuitry is divided into two major sections the system section and the analyzer section The system section contains the main processor CPU video display external interfaces power supply and front panel The analyzer section contains the digital signal processor DSP source output and analog inputs System Components The system section components are located in the left half of the chassis behind and below the CRT video display The card cage
123. sed All memory accesses and on board I O use the System bus The 80C186 generates 7 peripheral chip select strobes each covering 128 byte I O addresses PCSO enables on board I O peripherals front panel clock and printer port PCS1 enables the peripherals on the Video IO board PCS2 enables the AUX connectors on the System backplane PCS1 and PCS2 enable the Expansion data bus PCS4 and PCS5 enable the External DSP bus PCS4 enables processor addressable peripherals on the DSP board SR780 Network Signal Analyzer 2 6 Circuit Description U501 and U503 decode the on board I O locations enabled by PCSO These are the knob keypad and keyboard the clock the printer port and the system status port U508 is a wait state generator Extra wait states are generated by all I O accesses These extra wait states are canceled if the access is to the External bus The Video_Rdy signal also ends the wait generation Video_Rdy signals that the graphics processor on the Video IO board has acknowledged an IO cycle and is ready Interrupts generated by system peripherals on both the CPU and Video IO boards are combined in U505 into a single prioritized interrupt The highest priority pending interrupt will be encoded on U505 s outputs and read via the status port U608 The UART directly interrupts the processor since it can never be masked String ROM U801 and U802 are 256 kbyte EPROMS containing the on screen help information These
124. space key If this does not fix the problem continue Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding Release the bar which secures the boards in place See Figure 3 1 to locate the CPU board it s next to the Power Supply board Remove the CPU board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Replace the bar which secures the boards in place Replace the top lid and refasten the eight lid screws Reset the unit by turning the power ON while holding down the backspace key Service Procedure D2 Battery Check l Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of t
125. st results Auto Offset must be left enabled On in the Input More menu Disabling Auto Offset may invalidate the results of some tests The Test Record Make a copy of the SR780 Performance Test Record at the end of this section Fill in the results of the tests on this record This record will allow you to determine whether the tests pass or fail and also preserve a record of the tests If A Test Fails If a test fails you should check the settings and connections of any external equipment and if possible verify its operation using a DVM scope or some other piece of test equipment After checking the setup repeat the test from the beginning to make sure that the test was performed correctly If the test continues to fail contact Stanford Research Systems for further instructions Make sure that you have the unit serial number and firmware revision code handy Have the test record on hand as well SR780 Network Signal Analyzer Performance Tests 1 5 SR780 Network Signal Analyzer 1 6 Performance Tests SR780 Network Signal Analyzer Performance Tests 1 7 1 Self Tests The self tests check the analyzer hardware These are functional tests and do not relate to the specifications These tests should be run before any of the performance tests Note that the Test menu offers more tests than are required here Only those tests which require no additional equipment are discussed in this section The computer interface a
126. t it s heavy Lower the new CRT enclosure into the chassis and slide it forward Make sure that the slots in the enclosure overlap the mounting screw holes along the sides Insert the four screws which secure the enclosure Do not tighten them Gently slide the CRT enclosure forward until the front of the CRT just touches the plastic anti glare screen Slide the CRT back 1 8 so that the front of the CRT is just behind the anti glare screen Tighten the four screws to secure the enclosure in place Connect the CRT cable to the System backplane behind the CRT enclosure Make sure that the cable is locked into place 10 Replace the top lid and refasten the eight lid screws Service Procedure B2 CRT Check i Service Guide Turn the power OFF SR780 Network Signal Analyzer 3 14 Service Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Turn the power ON Use the DVM to check the 12V power supply to the CRT See Figure 3 1 to locate the Power Supply board Measure the 12V test point on the Power Supply board relative to the chassis The voltage should be within 5 of nominal If the 12V supply is fine proceed to Procedure B1 and replace the CRT assembly If the 12V supply is not within nominal check the supply voltage without the CRT connected Turn the power OFF Remove
127. t Description SR780 Network Signal Analyzer Service Guide 2 3 Overview The SR780 s circuitry is divided into two major sections the system section and the analyzer section The system section contains the main processor CPU video display external interfaces power supply and front panel The analyzer section contains the digital signal processor DSP source output and analog inputs System Components The system section components are located in the left half of the chassis behind and below the CRT video display The card cage behind the CRT contains the power supply main CPU card and the video IO card The cards are interconnected by a backplane board under the card cage The disk drive is mounted to a small board beneath the CRT This card can be removed from the front The keypad connects to the disk board at the front of the chassis Figure 2 1 System Components Chassis Top View CPU Video IO Power Supply System Backplane CRT Enclosure Disk Card Keypad Board Disk Drive Front Analyzer Components The analyzer section is in the right half of the chassis directly behind the keypad A card cage contains the DSP board and two identical analog input boards The analyzer boards are interconnected by a backplane board under the card cage This backplane extends all Service Guide SR780 Network Signal Analyzer Circuit Description the way to the front panel BNC connectors The analyzer backplane co
128. tal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Service Guide Parts List 4 31 Analog Input Board Parts List RefNo SRS Part No Component Description 4 00158 407 4 00210 407 4 00696 407 4 00471 401 4 00471 401 4 00138 407 4 00138 407 4 00154 407 4 00154 407 4 00031 401 4 00107 402 4 00107 402 4 00031 401 4 00706 407 4 00269 407 4 00108 402 4 00108 402 4 00108 402 4 00108 402 4 00215 407 4 00706 407 4 00215 407 4 00706 407 4 00021 401 4 00042 401 4 00042 401 4 00042 401 4 00021 401 4 00021 401 4 00054 401 4 00031 401 1 00173 150 1 00173 150 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 1 00143 101 Service Guide 10 10 100 237 4 64K 150 150 150 150 909 237 909 237 1 0K 15K 15K 15K 1 0K 1 0K 200K 100 8 PIN MACH 8 PIN MACH TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK TEST JACK Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM R
129. the 8 bits of the data U601 then latches the serial data in U601 and interrupts the processor Only keyboards which operate in the PC or 8088 mode will function with this interface Speaker The speaker is driven by a timer on the 80C186 The timer outputs a square wave which is enabled by U507A and drives the speaker through Q705 SR780 Network Signal Analyzer Service Guide Circuit Description 2 7 Clock Calendar U702 is an MC146818 real time clock chip which keeps track of time and date The time base is a 32 768 kHz oscillator made by U706 Both U702 and U706 are battery backed up Reset Battery Switch U701 is the processor supervisor Power on reset is detected by U701 and signaled to the processor via Pwr_Reset In addition the chip enables to the battery backed up memory U401 and U402 are protected by U701 Q701 provides normal 5V power to the battery circuits when the power is on Printer Interface The printer interface is a normal Centronics style parallel port Output data is buffered by U703 an LS octal latch Output control bits are buffered by the open collector driver U704 and input control bits are discriminated by U705A and U705B Expansion Connector The 120 pin connector carries all of the necessary interconnections to the System backplane Both the Expansion and External buses are carried off board via this connector Power is also delivered through this connector Service Guide SR780 Network Signal Analyzer 2
130. the CRT cable from the connector on the System backplane behind the CRT enclosure Turn the power back ON Measure the 12V test point on the Power Supply board relative to the chassis The voltage should be within 5 of nominal If the 12V supply is fine proceed to Procedure B1 and replace the CRT assembly If the 12V supply is still not within nominal turn the power OFF replace the CRT cable and proceed to Procedure Al Power Supply Replacement Service Procedure C1 Keypad Check 1 Mm 10 11 Perform the Keypad check in the System lt Diagnostics gt menu If the test passes then the keypad is OK If the test fails or cannot be completed then proceed Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards Remove the two hex screws which connect the handle arms to the chassis Remove the handle by pulling the arms apart slightly Remove the eight screws which secure the front panel bezel to the chassis These screws are exposed when the lid is removed There are two screws along each side and the top and bottom Remove the front panel bezel by pulling it slowly off towards the front The keypad is attached to the bezel There is a ground wire and cable extending from the keypad back to the main chassis Th
131. tlet ground to protect against electrical shock Always use an outlet which has a properly connected protective ground Service Do not attempt to service or adjust this instrument unless another person capable of A providing first aid or resuscitation is present Do not install substitute parts or perform any unauthorized modifications to this STOP instrument Contact the factory for instructions on how to return the instrument for authorized service and adjustment Fan The fans in the SR780 are required to maintain proper operation Do not block the vents in the chassis or the unit may not operate properly Service Guide SR780 Network Signal Analyzer SR780 Network Signal Analyzer Service Guide Contents Safety and Preparation For Use i Contents iii Table of Figures v Chapter 1 Testing Getting Ready 1 3 Self Tests 1 7 DC Offset 1 9 Common Mode Rejection 1 11 Amplitude Accuracy and Flatness 1 13 Amplitude Linearity 1 17 Anti alias Filter Attenuation 1 19 Frequency Accuracy 1 21 Phase Accuracy 1 23 Noise and Spurious Signals 1 25 Sine Source 1 29 Harmonic Distortion 1 31 SR780 Performance Test Record 1 33 Chapter 2 Circuit Description Overview 2 3 CPU Board 2 5 Video IO Board 2 8 Power Supply Board 2 10 DSP Board 2 12 Analog Input Boards 2 15 Chapter 3 Service Before Proceeding With Service 3 3 Troubleshooting Table 3 4 Circuit Board Locations 3 8 Service Procedures 3 10 Caution 3 10 Required Equipment 3 10 Power Sup
132. tor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Electrolytic 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Cap Monolythic Ceramic 50V 20 Z5U Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 Capacitor Monolythic Ceramic COG 1 SR780 Network Signal Analyzer 4 24 Parts List Analog Input Board Parts List RefNo SRS Part No Component Description 5 00148 545 5 00219 529 5 00219 529 5 00023 529 5 00023 529 5 00100 51
133. u hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg SR780 Network Signal Analyzer 4 6 Parts List CPU Board Parts List RefNo SRS PartNo Value Component Description 3 00594 340 MAX693A Integrated Circuit Thru hole Pkg 3 00900 340 DS12C887 Integrated Circuit Thru hole Pkg 3 00263 340 DS75451N Integrated Circuit Thru hole Pkg 3 00039 340 74HC14 Integrated Circuit Thru hole Pkg 0 00089 033 4 Tie 0 00373 000 CARD EJECTOR Hardware Misc 3 00046 340 74HC374 Integrated Circuit Thru hole Pkg SR780 Network Signal Analyzer Service Guide Parts List 4 7 Video lO Board Parts List This section covers schematics MVID 10 through MVID 14 in Chapter 5 RefNo SRS Part No Value Component Description 5 00134 529 100P Cap Monolythic Ceramic 50V 20 Z5U 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U 5 00219 529 01U Cap Monolythic Ceramic 50V 2096 Z5U 5 00218 529 120P Cap Monolythic Ceramic 50V 2096 Z5U 5 00134 529 100P Cap Monolythic Ceramic 50V 2096 Z5U 5
134. wer ON The fans should turn and the red LED at the top of the board should be ON If the fans do not turn or the LED stays off turn the power OFF and remove the power cord Check the AC power connector and transformer connector integrity You may need to remove the Power Supply board to do this See Procedure A1 for details on removing the Power Supply board 8 Check the voltages on the power supply test points This procedure measures the supply voltages under load all other boards are present and with all grounding paths present If the DSP or Analog boards are not present then the voltages labeled ANLG CH1 30V CH2 30V and DIG must be measured relative to the AGND CHIRET CH2RET and DGND test points Assuming that all other boards are present connect the negative lead of the DVM to the chassis Use the positive lead to measure the test points along the top of the power supply board starting at the rear Digital Power Test Point Nominal 12V 12V 5 5V 5V 5 12V 12V 5 5V 5V 5 Ground OV ANLG Power Test Point Nominal 28V lt 23V 28V gt 23V 20V 20V 5 20V 20V 5 AGND OV CH2 Test Point Nominal 30V 30V 5 RET OV CH1 Test Point Nominal 30V 30V 5 RET OV DIG Power Test Point Nominal 28V lt 23V 28V gt 23V 20V 20V 5 20V 20V 45 DGND OV 9 Ifthe supplies check ok then replace the top lid and refasten the eight lid screws
135. wer cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the front and two at the rear Remove the lid by pulling the lid towards the back and upwards See Figure 3 1 to locate the Power Supply board Make sure that the red LED at the top edge of the board is OFF before proceeding Release the bar which secures the boards in place See Figure 3 1 to locate the Video IO board it s farthest from the Power Supply board Remove the Video IO board by using the card ejectors to release the board and pull the board up and out Insert the new board making sure to align the board edges with the plastic card guides before pressing the board into place Make sure that the board is seated completely in its socket Replace the bar which secures the boards in place Replace the top lid and refasten the eight lid screws 10 Reset the unit by turning the power ON while holding down the backspace key Service Procedure F1 DSP Board Replacement Service Guide 1 Before replacing the DSP board reset the unit by turning the power OFF and ON while holding down the backspace key If this does not fix the problem continue SR780 Network Signal Analyzer 3 18 Service 2 8 9 Turn the power OFF Remove the power cord from the power entry module Remove the eight black screws which secure the top lid There are four screws on each side two at the f
136. z 1000 mV 0 3 dBV 0 3 dBV 11 Harmonic Distortion Fundamental DispA THD DispB THD Upper Limit 10 24 kHz lt 80 dB SR780 Network Signal Analyzer Performance Tests 1 35 SR780 Network Signal Analyzer Chapter 2 Circuit Description This chapter provides descriptions of the circuitry in the SR780 Each circuit board s function and operation is discussed The schematics for each board are shown in Chapter 10 In This Chapter Overview 2 3 DSP Board System Components 2 3 Digital Signal Processor Analyzer Components 2 3 Timing Signal Generator Schematic Diagram Locations 2 4 I O Interface CPU Board 2 5 Trigger Source Generator e Sien E Interface To CPU 1 O Map 2 5 Analog Input Boards String ROM 2 6 Input Amplifier Keypad Interface 2 6 Gain Stages And Attenuators Spin Knob 2 6 Anti Aliasing Filter Keyboard Interface 2 6 A Weighting Filter Speaker 2 6 A D Converter Clock Calendar 2 7 1 O Interface Reset Battery Switch 2 7 Power Printer Interface 2 7 Expansion Connector 2 7 Video IO Board 2 8 Video Graphics Interface 2 8 Disk Controller 2 8 GPIB Interface 2 9 RS232 Interface 2 9 Expansion Connector 2 9 Power Supply Board 2 10 Caution 2 10 Removing the Power Supply 2 10 Power Supply Connector 2 10 Test Points 2 10 System Power 2 10 Analog Power 2 10 2 1 2 12 2 12 2 12 2 13 2 13 2 13 2 13 2 15 2 15 2 15 2 16 2 16 2 16 2 16 2 17 Service Guide SR780 Network Signal Analyzer 2 2 Circui

SR780 Service Manual - Stanford Research Systems

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