Home

TEK DM 5120_5520_svc_sm

1. e 07 CUSTONER SERVICE ASSEMBLIES EE 186 2833 xx 426 2302 OPTIOWAL ACCESSORIES cee 012 1296 00 5120 4520 Service flanual NANE amp DESCRIPTION NFR CODE Rear Panel Assenbly not shaun 80009 Includes Panel Rear Marker Varning lop Left Front Sect flssy not shoun 80009 Includes Frane Section Left Varning Calibration Lead Set Banana to Kelvin not shoun 80009 ncludes Cable Intct Ban to Kel Red Cable Intet Ran to Kel Alk 306 5833 xx 426 2302 xx 012 1296 00 8 5 Replaceable Mechanical Parts Fig amp Index Tektronix No Part No 1 1 426 2289 00 211 0503 00 3 361 1507 00 4 213 0107 00 5 334 7564 00 6 334 7342 00 7 348 1068 00 8 367 0398 00 9 211 0467 00 10 367 0397 00 11 212 0144 00 12 348 0430 00 13 200 3646 00 14 211 0504 00 15 212 0023 00 18 mme a 17 210 0586 00 18 212 0515 00 19 210 0805 00 20 210 0812 00 21 166 0227 00 22 407 3420 00 23 211 0012 00 24 211 0025 00 26 210 0202 00 27 210 0586 00 28 214 3312 00 386 5949 00 29 174 1709 00 30 211 0295 00 31 210 0405 00 32 210 0054 00 33 210 0850 00 35 211 0008 00 36 214
2. 2 6 Power Up Self 4 6 Section 3 CALIBRATION Program 33 Self Diagnostic Program 4 6 SE 3 1 Power Supplies y sen te a veo guts 4 10 Calibration 3 1 Signal Conditioning 4 10 Environmental Conditions 3 1 Digital and Display Circuitry Checks 4 10 Recommended Test Equipment 3 1 Section 5 OPTIONS Internal Adjustments eee 3 2 Preparation for Calibration 3 2 Section 6 REPLACEABLE ELECTRICAL PARTS Calibration Mode Program 36 3 2 Section 7 DIAGRAMS AND CIRCUIT BOARD Front Panel Calibration ILLUSTRATIONS Command Sequence 3 3 GPIB Calibration Command Sequence 3 3 Section 8 REPLACEABLE MECHANICAL PARTS CHANGE INFORMATION DM 5120 5520 Service Manual iii LIST OF ILLUSTRATIONS Fig 1 1 Simplified Block Diagram 1 1 Fig 2 5 Connections for TRMS Fig 1 2 Input Configuration during 2 and AC Current 2 2 0 2 6 4 Terminal Resistance Fig 3 1 Volts Calibration Measurement 1 2 Configuration 3 4 Fig 1 3 Resistance Measurement Simplified Fig 3 2 Resistance Calibration
3. iiie 1 3 Configuration u a 3 6 Fig 1 4 JFET 1 4 Fig 3 3 Volts Calibration Fig 1 5 Multiplexer Phases 1 5 Configuration enn 3 8 Fig 1 6 A D Converter Simplified Fig 3 4 AC Volts High Frequency Schermatic eren 1 6 5 3 8 Fig 2 1 Connections for Fig 3 5 DC Current Calibration DC Volts Check 2 2 Configuration eee 3 10 Fig 2 2 Connections for TRMS Fig 3 6 AC Current Calibration AC Volts Check MENORES 2 3 Configuration MP 3 11 Fig 2 3 Connections for Ohms Check 2 4 Fig 4 1 Series Pass Transistor Replacement 4 4 Fig 2 4 Connections for DC Current Check 2 5 Fig 4 2 IEEE handshake sequence 4 11 LIST OF TABLES Table 1 1 INPUT BUFFER AMPLIFIER U35 Table 2 6 LIMITS FOR TRMS GAIN CONFIGURATION 1 5 AC CURRENT 2 6 Table 2 2 LIMITS FOR DC VOLTS CHECK 2 2 Table 4 1 RELATIVE SUSCEPTIBILITY TO Table 2 4 LIMITS FOR OHMS 2 4 STATIC DISCHARGE DAMAGE 4 1 Table 2 5 LIMITS FOR DC CURRENT Table 4 2 RECOMMENDED TROUBLE CHECK pM 2 5 SHOOTING EQUIP
4. Static Sensitive Devices Sae Martenance Section P O 420 DIGITAL BD POWER SUPPLY amp OPTOISOLATORS DIGITAL 2 Table 7 4 ANALOG 1 ANALOG BOARD ASSEMBLY A30 CIRCUIT SCHEMATIC BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION C38 D4 3D R19E B3 3C C53 A2 2D R20A B5 2 R20B B5 2 F332 B8 OFF BD 8208 C4 2C R20C 5 2 B8 OFF BD R20E 2 2 B8 OFF BD R21 B5 3D J3 B8 OFF BD R23 C3 3C J4 B8 OFF BD R25 B3 3D J5 B8 OFF BD R26 C3 3C J P10 B8 4E R45 C6 2D J P11 B8 4D R46 B5 3D JP12 B8 4D R47 5 20 J P8 B8 4E R48 B4 2 J P9 B8 4E R49 B3 3D R50 B1 3 K1 D6 3D R51 C1 3D K2 D6 3D R52 C4 3 K3 D7 2D RT1 07 2D L4 B7 4E TE1 A3 3D Q3 C5 2D 3 Q5 D5 3D Q6 D5 3D U2A C7 2C 07 06 20 U2B 5 2C Q8 2 U2C B6 2C D7 2D U2D B4 2 011 C4 2D U4A D1 3C Q12 C4 2D U4B C2 3c Q13 C6 2D U4C 3 Q16 C6 2D U4D 3 22 U20A B7 3D Q30 D2 3D U20B D3 3D Q31 D2 3D U B4 3C Q32 C1 3D U22B A4 Q33 B2 3D U22C C3 3C Q34 B5 3D U22D C3 3C Q35 B1 3D U24A B3 3C U24B C1 3C R1 D2 3D U24C C1 3 12 D7 3E U24D B2 3C R13 D5 3D U25A B1 3 R14 A5 3E 0258 C1 3C R15 A7 3E U25C B1 3C R16 C5 2C U25D B1 3C R17A D6 3D U42B C4 3 R17B C6 3D 042 C1 R17C C 3D U42D B1 3 215 R19B D2 3 VR1 D5 3C e Pig C1 30 Fig 7 3 A30 Analog Circuit Board Assembly DM 5120 5520 Service Manual 8 2 6 5 4 3 2 1 50
5. E Nu A P De J 0 SND m L Exc 5 Table 3 3 Set Up Fig 3 2 Fig 3 2 A Fig 3 2 wj Fig 3 2 B Fig 3 2 B Fig 3 2 B Fig 3 2 B RESISTANCE CALIBRATION DMM Calibration Point 190 0000 0 000 0000 Q 1 900000 0 000000 19 00000 00 00000 190 0000 000 0000 1 900000 0 000000 19 00000 00 00000 100 000 000 000 f T 4 4 7 5 p i I NIS H Vf OT 2 ler 4 f A 4 2 a m 22 DM 5120 5520 Service Manual Resistance Calibrator Setting 190 0 Short 0 0 1 9 Short 0 0 19 Short 0 0 190 Short 0 0 19 Short 0 0 19 Short 0 0 100 Short 0 0 Calibration IEEE 488 Bus Command OHMS RANGE 1 CAL FIRST 190 CAL LAST 0 OHMS RANGE 2 CAL FIRST 1 9E3 CAL LAST 0 OHMS RANGE 3 CAL FIRST 19E3 CAL LAST 0 OHMS RANGE 4 CAL FIRST 190E3 CAL LAST 0 OHMS RANGE 5 CAL FIRST 1 9E6 CAL LAST 0 OHMS RANGE 6 CAL FIRST 19E6 CAL LAST 0 OHMS RANGE 7 CAL FIRST 100E6 CAL LAST 0 3 7 Calibration 3 Calibrate AC Volts a Select ACV function b Select ACV range of 300 mV c Connect the DMM to the AC calibrator as shown in Fig 3 3 d Select Program 36 The display prompts 300 0000 mV e Set the
6. INPUT SENSE HI lt gt 755 Ou EZ y ves EEE NL 59 B1 212 Em gt 3U RELAY 100K OSV VN Se R13 SU r 5 1 50 1 UN 8128 4 1415 oO Ds OHM RELAY a es 150 150 y 5U 2 6U 3 4 2 1H 5 12 10UR u22 o gt RMS Q 1 SUR 9 Qu 5 AC cl 100K SENSE 15U L4 T JZP8 11 2 1 150 OHMS SENSE HI 85252855 U20 8 3 t J P9 J2 VOLTS OHMS 5 3 1 3 e OHMS SENSE LO gt gt 6 35 J P1 U 1SU 159 2 9 INPUT LD C1 as INPUT BUFFER 15U 15U C53 Q v 4 13 5 100 022 5 gt 12 8 COMPONENT NUMBER EXAMPLE 3 1 SUR IS 5 UOLTS REGULATED AND SUPPLIED BY v12 NS SENSE LD 271 2 10UR IS 10 UOLTS REGULRTED CURRENT SUPPLIED BY U11 lt gt U4D 11 2 6 Chass meynied compenents have ne Assembly Number 12 end of Reglaceable Parts ust Static Sensitive Devices dos Ms 10UR P O A30 ANALOG BD DM5120 5520 ANALOG 1 Table 7 5 ANALOG 2 lt gt ANALOG BOARD ASSEMBLY A30 CIRCUIT SCHEMATIC BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION 14 D1 2 R27 B1 2D 15 02 2 R28A C6 3C C16 C1 2C R28B B6 3C C
7. Refer to Figure 4 2 for required Handshake sequence conditions DATA SOURCE DATA SOURCE VALID NRFD ACCEPTOR NRFD ACCEPTOR DATE DATA TRANSFER TRANSFER BEGINS ENDS OD s en to Fig 4 2 IEEE handshake sequence DM 5120 5520 Service Manual 4 11 Maintenance Table 4 6 DISPLAY CIRCUITRY CHECKS Step Item Component Required Condition Remarks 1 U4 and 05 pins 2 9 14 5V 5 5 V supply 2 P14 pins 6 11 thru 24 Variable pulses Segment drivers 3 Ut pins 6 16 Variable pulses Digital drivers 02 pins 4 thru 7 14 thru 17 4 UB pins 3 4 5 6 10 11 12 1 ms negative going pulse every U4 PINS 1 3 4 5 10 ms 5 P14 pin 7 50 Press 51 S5 S12 S9 or 515 Pulse present when button button pressed 6 P14 pin 5 S1 Press S2 S6 S10 513 514 Pulse present when button button pressed 7 P14 pin 3 S2 Press S3 S7 S11 S16 or S17 Pulse present when button button pressed 8 P14 pin 9 S3 Press S4 or S8 button Pulse present when button pressed _ _ _ _ F 4 12 5120 5520 Section 5 OPTIONS There are no options available for the DM 5120 5520 at this time Future options will be listed in this section DM 5120 5520 Service Manual rene Section 6 REPLACEABLE ELECTRICAL PARTS PARTS
8. digital The INPUT CONDITIONING CURRENT s gt SHUNTS 1 ATTENUATION AC DC CONVERSION t i l HI gt DCV ATTENUATION MULTIPLEXER LO gt OHMS REF RESISTORS i CONTROL MiCROCOMPUTER 488 INTERFACE aee analog and digital sections are electrically isolated from each other by the use of opto isolators for con trol communications Separate power supplies for the analog and digital sections ensure proper isolation The analog section consists of the signal condition ing circuits multiplexer input amplifier A D converter and control circuitry The heart of the digital section is a 68B09 microprocessor that supervises the entire operation of the instrument Additional digital circuitry includes the display and IEEE 488 interface INPUT AMPLIFIER A D CONVERTER ANALOG FRONT PANEL KEYS DISPLAY Fig 1 1 Sim
9. P14 P14 AP14 214 P14 14 SU 2 V CLOCK 5 DATA T ToS 50 51 DENOTES DIGITAL COMMON 3 y DENOTES DISPLAY COMMON A10 DISPLAY BD FRONT PANEL amp DISPLAY lt gt Table 7 2 DIGITAL 1 D DIGITAL BOARD ASSEMBLY A20 CIRCUIT SCHEMATIC BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION C1 D7 2D R13G C8 3D C2 B7 20 R13H A4 30 C3 A5 2C R14 C2 C4 B6 R15 B2 3 5 5 C6 D1 3E U1 D7 3D C7 C3 3C U3A A2 3C C8 B4 3D U3B A5 3C C9 B8 3D U4 C6 3E C10 B8 3D U5 D2 3E C11 A8 3E U6 D1 3E C21 A8 3E U7 D1 3E U8 3D CR3 A4 2D 09 C6 3E CR4 A4 2D U10 C7 3D CR5 A4 2D U11 C5 3C CR6 A4 2D U12 B2 U13A A6 4C J8 A4 OFF BD U13B A3 4C A4 OFF BD U13C B6 4C J13 A 3C U13D 4 414 5 4 J15 A4 4E U13F A6 4C J17 D1 3EE U14A B3 3C U14B B2 3C R1 A4 2C U14C A6 3C R2 A4 3C U14D A6 3C R12A 3D U14E B3 R12B A3 3D U14F 82 3C R12C A3 3D U15 B3 R12D A3 3D U16 C3 3 R12E A4 3D U17B D6 3D R13A 30 U17C B4 3D R13B C8 3D U17D D5 3D R13C 3D U19 8 R13D C8 3D U20 C6 3D 1 f R13E C8 3D R13F C8 3D Y1 B8 30 Fig 7 2 A20 Digital Circuit Board Assembly DM 5120 5520 Service Manual 90 Y1 8 0000MHz C10 15 CHASSIS 5120 5520 11 0 1UF DD Go Bs g 014 14 6 74HC04 5 IN U14 14 STROGE IN 8 oc 74HC04 5 COUNTS BACK STROBE
10. s a a H s CUSTOMER SERVICE KITS poat Order by desc Front Panel Asserhly not shown Keithley 5120 Includes Connector Connector Jack Black Connector Jack Red Connector Jack bhite Cable 12 0 to Fuse Cable BHC to Digital Board Fuse Cartridge 3A SLO Fuseholder Cartridge Carrier Fuse Overlay Front Panel Subpanel front rder hy desc Connector Kit not shown Keithley 51270 Includes Connector Connector Jack Black Connector Jack Red Connector Jack White Fuse Cartridge 3A SLO Fuseholder Cartridge Carrier Fuse Circuit Bd Pur Supply Interface Circuit Bd Interface rder hy desc 1 Interconnect Cables not shoun Keithley 5120 KIT3 Includes Cable Pouer Supply Cable Cable Display to Digital Bd Cable Analog to Digital Bd Cable to Digital Cable 8J 12 0 to Fuse Choke Assy Red Choke Assy Grey Choke fissy Orange Choke Assy Black White eem Order by desc 1 Mounting Tool Meter Jack not shown Keithley 55425 Dri 5120 5520 Service Manual FIG amp TEKTRONIX SERIAL HO QTY INDEX PART MO EFFECTIVE DISCOMT Replaceable Mechanical Parts Wr Part ate air Gie a
11. 1 Unsolder and remove the transistor being replaced from the circuit board 2 Carefully bend the new transistor leads according to the dimensions in Fig 3 1 3 Apply a new adhesive insulator plate to the tran sistor side having exposed metal 4 Reinstall the circuit board into the power supply assembly 4 3 Maintenance 5 Insert the leads of the replacement transistor into the circuit board holes with the insulating plate tacing the metal chassis 6 Reinstall the transistor clamp 7 Solder the transistor onto the board applying min imum heat 8 Reinstall the assembly into the power module cabinet Reinstall the handle assembly Side Cover Removal The two side panels are snapped into the top and bottom rails of the DM 5120 5520 To aid removal there are cutouts along each of long edges of covers To remove insert tweezers or a small straight edged screwdriver into the cutout near the back edge of the cover and carefully pry the cover away from the rail To replace covers insert the front edge of the cover into the groove along the inside edge of the front assembly Then press the cover down over the rails CORRECT TRANSISTOR LEAD ANGLES 0 370 CORRECT RELATIONSHIP TO CIRCUIT BOARD Fig 4 1 Series Pass Transistor Replacement Internal Fuse Replacement Remove the DM 5120 or DM 5520 from its power module The fuses are located under the cove
12. 150 C1 18U 150 o 5 sunU RELAY 1 S 4 hz a a I 5 amp li2 59 Ed 150 15U S 15u 1 151 CRI 50 th USD 7 2 30tunc zopsn 1339 2 a 5271 100K R23 Y 1UF CURRENT VON EE RR a 10 gt NUMBER EXAMPLE Component Number R1234 ANNE Numba nu nb xe Lassus came nfi hare Assemblv pari see Paris Lexi ISPLTOLS et Static Sensitive Devices See Mimenarce P O A30 ANALOG DM5120 5520 ANALOG 2 O Table 7 6 ANALOG 3 ANALOG BOARD ASSEMBLY A30 CIRCUIT SCHEMATIC PI BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION C18 B7 3D R38C C8 3D C19 C6 D R38D A8 3D C20 C6 3D R38E B8 3D C21 B4 3C R38F B7 3D C22 B3 R38G A7 3D C23 R38H 7 3D B6 3D R38J 7 30 C26 B6 3D R39 D7 3C C27 D3 2C R40 D8 3C C50 D7 3D R41 D6 3D C51 D7 aD R42 C6 3D C52 D7 3D R43 B6 3D C60 C4 3B R44 B6 3D CR4 3D U13 B5 3C 5 C8 30 29 B2 3C U30 D2 3 J P20 D5 4B U31 2 U32 B2 3C P15 D5 4B U33 B2 3C U34 3C Q19 D8 3D U35 D7 Q41 D8 3D U36 7 30 U37A 7 30 R10A B4 3C U37B B7 3D R1 08 B4 3C U44A 7 3C R1 B4 3C U45A D4 2C R36 B5 3C R37 B5 3C VR3 A7 3D R3
13. 33 00 3e Di 29 5U 5U Lees LS 9 9 50 141014 141014 741004 4 04 DATA 1N914 1N914 CR4 STRDBE CRS 1 Static Sensitive Devices 1N914 1N914 See Maintenance Section CGUNTS BACK Rio CHASSIS UNUSED GATES COMPONENT NUMBER EXAMPLE Component Number 5UC Chassis components Nave ne Assembly Number end of Replaceable Electncal Parts List DIGITAL 1 gt EXTERNAL TRIGGER CONNECTS TO MEASUREMENT PANEL MOUNTED LUG COMPLETE DATA 50 51 52 53 gt JCD N Ov JEN SINA AU AN DD 5 c at nc e lar ine C nc n foe C NC QT gt Table 7 3 POWER SUPPLY amp OPTOISOLATORS DIGITAL 2 lt gt DIGITAL BD ASSEMBLY 20 CIRCUIT SCHEMATIC BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION 1 C3 4C J15 D1 4E AT1B BB3 4C J16 A8 4E AT2 B3 4C J16 D8 4E D3 4 R3 C3 4 12 C2 4 R4 C3 4 C13 B3 4 R5 B2 4C C14 C6 4E R6 C2 4D C15 B6 4D R7 B2 4C C16 B6 4D R8 D3 4C C17 C5 4D R9 B3 4C C18 B5 4D R10 D2 4D C19 B5 4D C20 C7 4E T1 C7 4E C22 C6 4D C23 C6 4E U2A 4 C24 B2 4D U2B A2 4 25 82 4 U2C D2 4C C26 C2 4 U2D B2 4 U2E C2 4 C6 4D U2F B2 4C CR2 B6 4D U18 D7
14. Electrical Parts List A numbering method has been used to identify assembiies subassemblies and parts Examples of this numbering method and typical expansions are illustrated by the following Example a component number A23R1234 A23 R1234 Assembly number Circuit number Read Resistor 1234 of Assembly 23 Example b component number A23A2R1234 A23 A2 1234 Assembly Subassembly Circuit number number number Read Resistor 1234 Subassembly 2 ot Assembly 23 5120 5520 Service Manual Only the circuit number will appear on the diagrams and board illustrations Each diagram circuit board illustration is clearly marked with the assembly number Assembly numbers are also marked on the mechanical exploded views located in the Mechanical Parts List The component number is obtained by adding the assembly number prefix to the circuit number The Electrical Parts List is divided and arranged by assemblies in numerical sequence e g assembly A1 with its subassemblies and parts precedes assembly A2 with its sub assemblies and parts Chassis mounted parts have no assembly number prefix and are located at the end of the Electrical Parts List TEKTRONIX PART NO column two of the Electrical Parts List Indicates part number to be used when ordering replace ment part from Tektronix SERIAL MODEL NO columns three and four of the Electrical Parts List Column three 3 indic
15. IVE UNUSED GATES 110 617 1NH U DOE 1 Yoo sg 15 16 B 01 196 602 185 622 zc R54 R 10 15y ku 7 E RH 2 2BK 196 662 R57 136 662 R2 968k 196 602 4 R10E 2 15 R10F 1 7 15 0 1UF 0 1 SVR COMPONENT NUMBER EXAMPLE Component Number P A23 A2 R1234 ee y r umet Tutus ann rd Com peng niy a w na kasa mbi parha rr cod of Pacts Lest Slatic Sensitive Devices Ser Maintenaneoe ANALOG 4 D neooooocoo Fig 7 4 A40 Power Connector Assembly and A50 GPIB Connector Assembly DM 5120 5520 Service Manual TO POWER MODULE PIG 13 PIG 11 045120 lt 5520 40 POHER CONNECTOR BD 18 17 1 4 e 4 17 ls 16 Pl D PIS 18 18 lt PIS 11 18 nc i TO 1 12 8 ra POWER 416 MODULE leg a plz 5 gt 8 10 ls gt ri 1515 Pi 11 leg s 2 I 19 1 17 3 217 B PIS 2 1 x 1 Pi COMPONENT NUMBER EXAMPLE Component Number ii Static Sensitive Devices dg See Secher Number id used U Assembly Number Ch
16. Table 7 7 ANALOG 4 D ANALOG BOARD ASSEMBLY A30 CIRCUIT SCHEMATIC BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION C1 D7 2 R56 D4 2B 2 7 3B R57 C3 2B D5 2B R58 D1 28 C4 D2 2 R59 5 2 5 1 3C R60 08 2B C6 A2 3C R61 01 28 C9 D5 2B R62 2B C10 C5 2B R63 B1 3B C11 B2 3C R64 3B C12 B2 3C R74 05 28 C29 D4 2B C30 D4 2B TP1 D5 2B C32 D4 2B TP2 D8 2C C5 2B 5 2B C34 A8 3B TP4 C1 3C C35 A7 3B C36 A7 3B U5A C7 2C C56 B2 3C 058 07 2 57 2 3C USC A4 2C C58 C2 3B USD A3 2 U6A C6 3B CR1 D5 2B eB C6 3B U6C B6 3B J P20 C1 4B U6D C6 3B U7A C7 38 15 C1 4B 078 C8 3B U8A 88 2B Q1 D4 2 U8B C4 28 D3 2 U11 A2 3C Q17 D2 2C U12 B2 3C Q18 B1 3C U16A 2C U16B 2C R2 28 U16C C5 2C R3 U17A B7 38 C3 2B U17B A7 3B R7 B3 2B U18A B6 3B R8 2C U18B B5 3B R9A D8 2B U19 D5 2B R9B C7 2B U43B A8 3B R9C D7 2B U43C B5 3B R9D C6 2B U43D C2 3B R9E 05 28 0448 8 3 R9G C3 2B 44 R9H C2 2B 0458 02 2 R10E B2 3 U45C C2 2C R10F B2 3C R10H B1 3C Y1 B8 3B R54 C4 2B DM 5120 5520 Service Manual _ 29 C30 15 55 i 10UF 5U lt 14 VED 14 10 74HCDC 3 Er 0427 10 gt 5 vo 24 Wee DM5120 5520 210 D
17. The dc signal is then applied to the multiplexer On the 300 mV and 3 V ranges the signal is routed through relay K5 and buffer U28A On the 3 V range the signal proceeds through analog switch U21C and buffer U26B before being applied to the TRMS con verter U27 On the 300 mV range the signal is detoured through analog switch U21A to U28B which is configured as a X10 amplifier The amplified sig nal then proceeds through analog switch U21B and buffer U26B to the TRMS converter U27 In the 30 V range the signal is applied to U26A Be cause analog switch U23C is open on this range amplifier U26A has a feedback resistance of 118 R32 which results in a gain factor of 1 10 The divided signal is then routed through analog switch U23B and buffer U26B to the TRMS converter On the 300 V range the signal is applied to U26A Because analog switch U23C is closed on this range amplifier U26A has a feedback resistance of 118 R32 in parallel with 13 R24 resulting in a gain factor of 1 100 The divided signal is then routed through analog switch U23B and buffer U26B to the TRMS converter OHMS Diagram 4 Resistance measurements are made using the ratio metric technique see Figure 1 2 When the resis tance function is selected a series circuit is formed between the ohms source a reference resistor and the external unknown resistance A current flows through the reference resistor and the unknown resis tanc
18. The entire calibration procedure may be performed without having to make any internal adjustments if high frequency 70 kHz has been verified as ex plained in step 4 Calibration can be performed by either of two methods 1 from the front panel Program 36 or 2 over the IEEE 488 bus GPIB To make internal adjustments you must operate the DM 5120 5520 outside the power module using the extender cables listed in Table 3 1 Preparation for Calibration 1 DM 5120 Only Insert instrument into the TM 5003 power module The DM 5520 contains its own power module 2 Check that the line selector on the power module cabinet is set to the correct voltage 3 Turn on the power and allow the instrument to warm up for at least two hours before continuing with the calibration procedure See Environmen tal Conditions above 4 Check that the instrument is set to the proper line frequency by running front panel Program 32 as follows Press front panel keys in this order PROGRAM LED on PROGRAM displayed 3 2 FREQ 50 HZ or 60 HZ displayed Use or to toggle to your correct line frequency NOTE If you changed the line frequency and want your change to remain the same when the in strument is again powered up run Program 30 SAVE CURRENT SETTINGS or send PONSAVE from the IEEE bus 5 Insert a small bladed screwdriver into the hole in the front panel marked CAL LOCK Push in light ly to enable the calib
19. To avoid electric shock hazard do not touch exposed circuitry The shield on the analog board is at input low potential and can have up to 500 V on it Use an insulated alignment tool to make the following adjustments Turn on the DMM j Select Program 2 and set digits to 5 1 2 k Select ACV function Select range of 300 C49 300 V AC RANGE HIGH FREQUENCY ADJUST C48 30 V AC RANGE HIGH FREQUENCY ADJUST Fig 3 4 AC Volts High Frequency Adjustments DM 5120 5520 Service Manual m Set the AC calibrator output to 100 000 V at 70 kHz Allow a few seconds for the voltage to stabilize n ADJUST C49 Fig 3 4 for a display reading of 100 000 V 20 250 V o Select ACV range of 30 V Calibration p Set the AC calibrator output to 10 0000 V at 70 kHz Allow a few seconds for the voltage to stabilize q ADJUST Fig 3 4 for display reading of 10 0000 V 20 0250 V r Repeat steps m through q until no adjustment 5 necessary Table 3 4 AC VOLTS CALIBRATION DMM ACV DMM Calibration Calibrator Voltage IEEE 488 Range Point Setting 500 Hz Bus Command ACV RANGE 1 300 mV 300 000 mV 300 000 mV CAL FIRST 300E 3 030 000 mV 30 000 mV CAL LAST 30E 3 ACV RANGE 2 3 V 3 00000 V 3 00000 V CAL FIRST 3 0 30000 V 0 300000 V CAL LAST 300E 3 ACV RANGE 3 30 V 30 0000 V 30 0000 V CAL FIRST 30 3 0000 V 3 00000 V CAL LAST 3 ACV RANGE 4 300 V 300 000 V 300 000 V CAL FIRST 300 30 000 V 3
20. U23A U25D Q32 CAL 03 X1 U23A U25C 032 SIG 04 X10 U23A U24B Q32 4 8 DM 5120 5520 Service Manual Function amp Range 3 mA DC 30 mA DC 300 mA DC DC 300 uA AC 3 mA AC 30 mA AC 300 mA AC 3 A AC DM 5120 5520 Service Manual Measurement Phase SIG ZERO CAL ZERO CAL SIG SIG ZERO CAL ZERO CAL SIG SIG ZERO CAL ZERO CAL SIG SIG ZERO CAL ZERO CAL SIG ZERO CAL SIG No Test ZERO CAL SIG No Test ZERO CAL SIG No Test ZERO CAL SIG No Test ZERO CAL SIG No Test Table 4 3 Cont DM 5120 5520 TROUBLESHOOTING MODE N Mode 01 02 03 04 01 02 03 04 01 02 03 04 01 02 03 04 01 02 03 04 01 02 03 04 01 02 03 04 01 02 03 04 01 02 03 04 Input Buffer Gain X10 X1 X1 X10 X10 X1 X1 X10 X10 X1 X1 X10 X10 X1 X1 X10 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 Relays Closed Range Switches Closed Q29 Q36 Q29 Q36 Q29 Q36 Q29 Q36 Q28 Q37 Q28 Q37 Q28 Q37 Q28 Q37 Q26 Q38 _ Q26 038 026 038 026 038 039 040 039 040 Q39 040 039 040 U23A 0210 0218 U23A U21D U21B U23A U21D U21B Q29 Q36 U21D U21B Q29 Q36 U21D U21B Q29 Q36 U21D U21B Q28 Q37 U21D U21B Q28 Q37 U21D U21B Q28 Q37 U21D U21B Q26 38 U21D U21B Q26 38 U21D U21B Q26 38 U21D U21B
21. 4 2 Microcomputer Diagram 2 1 6 Disassembly Instructions 4 3 Display Circuitry Diagrams 1 8 2 1 7 DM 5520 Only Power Supplies Diagram 1 7 Power Module 4 3 Side Cover Removal 4 4 PERFORMANCE CHECK Internal Fuse Replacement 4 4 osi re 2 1 Release Latch Handle and Services 2 2 1 Slider 4 4 Environmental 2 1 Rear Panel Removal 4 5 Recommended Test Equipment 2 1 Front Frame Assembly Removal 4 5 Preparation ee 2 2 Display Board Assembly A10 Removal 4 5 Check Procedures 2 2 Digital Board Assembly A20 Removal 4 5 1 Check DC Volts eere 2 2 Analog Board Assembly A30 Removal 4 5 2 Check TRMS Volts 2 3 Troubleshooting 4 6 Check Omsen 2 4 Disassembly for Troubleshooting 4 6 4 Check DC Current 2 5 Recommended Test Equipment 4 6 5 Check TRMS
22. 5120 5520 Service Manual INDENTATION SYSTEM This mechanical parts list is indented to indicate item re lationships Following is an exampie of the indentation sys tem used in the description column 12345 Name Description Assembly and or Component Attaching parts for Assembly and or Component END ATTACHING PARTS Detail Part of Assembly and or Component Attaching parts for Detail Part END ATTACHING PARTS Parts of Detail Part Attaching parts for Parts of Detail Part END ATTACHING PARTS Attaching Parts always appear in the same indentation as the item it mounts while the detail parts are indented to the right Indented items are part of and included with the next higher indentation Attaching parts must be purchased separately un less otherwise specified ABBREVIATIONS Abbreviations conform to American National Standards Institute Replaceable Mechanical Parts CROSS INDEX MFR CODE NUMBER TO MANUFACTURER Mfr 00779 INC 12327 FREEWAY CORP 73743 FISCHER SPECIAL MFG CO 74932 INDUSTRIAL SPECIALTIES INC 78189 ILLINOIS TOOL WORKS INC SHAKEPROOF DIV 80003 INC 83309 ELECTRICAL SPECIALITY CO SUB OF BELDEN CORP 83385 MFG INC GREER CENTRAL DIV 86928 MFG CO INC 93907 TEXTRON INC CAMCAR DIV TK0435 LEWIS SCREW CO 858 STAUFFER SUPPLY CO DIST 569 GERHART TOOL AND DIE KEITHLEY KEITHLEY INSTRUMENT DIV 2800 FULLING MILL PO BO
23. Q39 40 U21D U21B Q39 40 U21D U21B Q39 40 U21D U21B Maintenance Multiplex U25D Q32 U25D Q32 U25C Q32 U24B Q32 U25D Q32 U25D Q32 U25C Q32 U24B Q32 U25D Q32 U25D Q32 U25C Q32 U24B Q32 U25D Q32 U25D Q32 U25C Q32 U24B Q32 U25D Q32 U25C Q32 U25C Q32 U25D Q32 U25C Q32 U25C Q32 U25D Q32 U25C Q32 U25C 032 U25D Q32 U25C Q32 U25C Q32 U25D Q32 U25C 032 U25C Q32 Switches Ciosed 4 9 Maintenance Power Supplies Table 4 4 shows the various checks that can be made to the power supplies of the DM 5120 5520 In ad dition to the normal voltage checks it a good idea to check the various supplies with an oscilloscope for signs of noise or oscillations Signal Conditioning Checks These circuits can be checked by using the diagnos tic program Program 33 as explained above Digital and Display Circuitry Checks The digital and display circuit can be checked out by using the troubleshooting data in Tables 4 5 and 4 6 Table 4 4 POWER SUPPLY CHECKS Step Item Component Required Condition Remarks Set to 115 or 230 V as required Line voltage selection Q1 Power Module Line Switch 2 Power Module Line Fuse Check for continuity Remove fuse to check 3 Line Power Plugged into live receptacle power on NND V G_ o 4 Extender Cable Check for continuity 5 15 V Digital Sup
24. and DM 5520 instruments are referred to as DMM The following steps are for verifying the one year ac curacy specifications of the DM5120 or DM 5520 at 5 1 2d resolution for each of the five measuring func tions DC volts TRMS AC volts ohms TRMS AC amps and DC amps These procedures are intended for use by qualified personnel using accurate and reliable test equipment To prevent a shock hazard do not exeed 350 V between input low and chassis ground Some of the procedures in this section may expose the user to dangerous voltages Always con nect the shield side of the coax to the LO side of the output and input connectors Never touch the BNC connectors when calibrator output is active Use standard safety precautions when such dangerous voltages are encountered 1 Check DC Volts Test Equipment Required DC Voltage Calibrator BNC Coax cables and BNC to Banana Adapters CAUTION Do not exceed 300 V between the input and LO terminals or instrument damage may occur 2 2 a Press DMM keys as follows DCV LED on AUTO LED on PROGRAM LED on PROGRAM displayed 2 current digits displayed or to display 5 1 24 b Connect the DMM to the DC voltage calibrator as shown in Fig 2 1 DC VOLTAGE CALIBRATOR MODEL 5440 Fig 2 1 Connections tor DC Volts Check c Set the calibrator to 0 V and press the DMM NULL key LED on d CHECK DMM display reads 000 000
25. in this sec tion is intended to aid qualified service personnel to isolate a defective circuit or circuit section To aid in troublehooting schematic diagrams and component location drawings are located in subsequent sections of this manual Disassembly for Troubleshooting To gain access to the circuitry on most circuit boards you will have to remove the boards and reconnect the cables outside of the instrument frame Refer to the disassembly instructions in this section to remove a board then appropriately support the board and reconnect the cables Recommended Test Equipment Table 4 2 lists the test equipment recommended for troubleshooting the DM 5120 5520 Other equipment such as logic analyzers and capacitance meters could also be helpful especially in difficult situations In addition you will need extender cables see Table 3 1 for part numbers for operating the instrument outside of the power module Table 4 2 RECOMMENDED TROUBLESHOOTING EQUIPMENT rn ph SY Equipment Use Five function with 0 1 DCV accuracy 10 M ohm input impedance Power supply and DC voltage checks analog signal tracing continuity logic levels Digital and analog waveform checks Dual trace triggered sweep oscilloscope dc to 50 Mhz Digital frequency Checking clock counter frequencies TM 5003 or TM 5006 Power for DM 5120 only Power Module Power Up Self Test Upon power up the instrument will do a num
26. small wiring use only a 15 watt pencil type iron A higher wattage soldering iron can cause the etched circuit wiring to separate from the board base material and melt the insulation from small wiring Always keep the solder ing iron tip properly tinned to ensure the best heat transfer to the solder joint Apply only enough heat to remove the component or to make a good solder joint To protect heat sensitive components hold the component lead with a pair of long nose pliers be tween the component body and the solder joint Use a solder removing wick to remove excess solder from connections or to clean circuit board pads Semiconductors To remove the in line integrated circuits installed in sockets use an extracting tool This tool is available from Tektronix inc order Tektronix Part Number 003 0619 00 If an extracting tool is not available use care to avoid damaging the pins Pull slowly and evenly on both ends of the integrated circuit Try to avoid disengaging one end before the other IC s that are soldered in should be carefully unsoldered using commercially available de soldering tools H these tools are not available the pins in the may be clipped with diagonal cutters and the pins then in dividually removed from the board DM 5120 5520 Service Manual Disassembly Instructions To avoid electric shock hazard disconnect the power source and other instrumentation con nected to the instrument before disass
27. the power supply assembly that secure the circuit board to the chassis DM 5120 5520 Service Manual Maintenance 4 Disconnect from the circuit board the three con nectors going to the transformer 5 Slide the circuit board out of the power supply as sembly Voltage Selector Fuse Holder Assembly Removal 1 Remove the cabinet Refer to DM 5520 Power Module Cabinet Removal in this section of the manual 2 Disconnect the connectors from the terminals on the back of the voltage selector fuse holder as sembly labeling each wire NOTE The assembly has a locking tab on the top and bottom sides that secure it in the chassis hole Do not apply excessive force to the locking tabs Excessive pressure will reduce the strength of the plastic material 3 Push the top tab in carefully pulling gently on the assembly from the outside That side of the as sembly will be released Repeat to release the bot tom side Pull the assembly through the chassis hole to the outside taking care not to damage the capacitors Series Pass Transistor Replacement NOTE A new adhesive insulator plate must be applied to the transistor before installation To maintain proper insulating characteristics do not reuse the insulating plate from the transistor being replaced To replace a series pass transistor remove the cab inet then remove the circuit board Refer to Cabinet Removal and Circuit Board Removal in this section of the manual
28. tolerance Table 2 1 TEST EQUIPMENT REQUIRED Required for Description Performance Specifications These Checks Recommended Power DM 5120 only Tektronix TM 5003 or Module TM 5006 DC Voltage 300 mV 3 V 30 V 300 V ranges 15 DC Volts Fluke 5440A Calibrator ppm DC Current AC Voltage 300 mV 3 V 30 V ranges 20 Hz 0 1 Volts Fluke 5200A Calibrator 50 Hz 20 kHz 0 0296 100 kHz 0 33 TRMS AC Current AC Power 300 V range 20 Hz 0 12 50 Hz 20 TRMS AC Volts Fluke 5215A Amplifier kHz 0 04 100 kHz 20 196 Resistance 300 Q 3 ranges 215 ppm 30 Ohms Fluke 5450A Calibrator 32 ppm 300 range 225 ppm Current 300 p 3 ranges 0 025 DC Current Valhalla 2500E Calibrator TRMS AC Current Coax Cables 2 ea required All checks Tektronix PN 012 0057 01 BNC to dual 2 ea required All checks Tektronix PN 103 0090 00 banana adapter Se DM 5120 5520 Service Manual 2 1 Performance Check Preparation 1 5120 Only Insert instrument into TM 5003 or TM 5006 power module The DM 5520 con tains its own power module 2 Check that the line selector on the power module cabinet is set to the correct voltage 3 Turn on the power 4 Allow the instrument to warm up for at least two hours before continuing with the performance checks See Environmental Conditions above Check Procedures NOTE In the following procedure the DM 5120
29. 0 0000 V CAL LAST 30 DM 5120 5520 Service Manual Calibration 5 Calibrate DC Current a Select DCA function b Select DCA range of 300 pA c Connect the DMM to the DC current calibrator Fig 3 5 d Select Program 36 The display prompts 300 000 pA e Set the DC current calibrator to 300 000 pA Allow a few seconds for the voltage to stabilize f Press the ENTER key The display prompts 000 000 pA g Set the DC current calibrator to 000 000 pA Allow a few seconds for the voltage to stabilize LO pc VOLTAGE x CALIBRATOR CURRENT CALIBRATOR req 99995515535 MODEL MODEL 2500E 5440A DMM Fig 3 5 DC Current Calibration Configuration h Press the ENTER key The DCA calibration points are updated stored for the selected range and the DCA function returns to normal i Repeat steps d through h for the remaining DCA ranges using Table 3 5 as a guide Table 3 5 DC CURRENT CALIBRATION DMM DCA DMM Calibration DC Current IEEE 488 Range _ Point Calibrator Output Bus Command ll II M DCA RANGE 1 300 pA 300 000 300 000 CAL FIRST 300E 6 000 000 pA 000 000 pA CAL LAST 0 DCA RANGE 2 3 3 00000 mA 3 00000 mA CAL FIRST 3E 3 0 00000 mA 0 00000 mA CAL LAST 0 DCA RANGE 3 30 mA 30 0000 mA 30 0000 mA CAL FIRST 30E 3 00 0000 mA 00 0000 mA CAL LAST O DCA RANGE 4 300 mA 300 000 mA 300 000 m
30. 0 Hz Performance Check AC VOLTAGE CALIBRATOR POWER AMPLIFIER MODEL MODEL 5200A Fig 2 2 Connections for TRMS AC Volts Check d the reading is within the limits listed in Table 2 3 e Repeat the 290 mV measurement at the other fre quencies specified in Table 2 3 f Repeat the procedure for the 3 V 30 V and 300 V ranges by applying the respective AC voltages listed in Table 2 3 g CHECK the reading for each range should be within the limits listed in Table 2 3 Table 2 3 LIMITS FOR TRMS AC VOLTS CHECK Reading Limits 18 to 28 DMM Applied ACV Range AC Voltage 20 Hz 50 Hz 300 mV 290 000 mV 284 100 289 030 to to 295 900 290 970 3 V 2 90000 V 2 84100 2 89030 to to 2 95900 2 90970 30 V 29 0000 28 4100 28 9030 to to 29 5900 29 0970 300 V 290 000 V x 284 100 289 030 to to S 295 900 290 970 Do not apply 290 V at 100 kHz to the input This exceeds the VsHz limit of the instrument 200 Hz 10 kHz 20 kHz 100 kHz 289 465 289 465 288 640 283 900 to to to to 290 535 290 535 291 360 296 100 2 89465 2 89465 2 88930 2 85350 to to to to 2 90535 2 90535 2 91070 2 94650 28 9465 28 9465 28 8640 28 5350 to to to to 29 0535 29 0535 29 1360 29 4650 289 465 289 465 288 640 to to to 290 535 290 535 291 360 Maximum TRMS AC volt input at 100 kHz is 100 V On the 300 V range allowable readings with 100 V at 100 kHz applied to the input are 98 200 to 101 800
31. 012 595027 200 3646 00 435 ORDER DESCR 93907 78189 93907 12327 83309 80009 80009 93907 ORDER BY DESCR 211 041800 00 ORDER BY DESCR ORDER BY DESCR ORDER BY DESCR 166 0227 00 407 3420 00 ORDER BY DESCR TK0435 ORDER BY DESCR 86928 78189 00779 80009 80009 80009 73743 78189 12327 93907 80009 80009 80009 373 158 2 211 041800 00 552633 4 386 5949 00 174 1709 00 211 0295 00 12157 50 ORDER BY DESCR ORDER BY DESCR ORDER BY DESCR 214 1593 02 129 0160 00 348 0640 00 TK1569 ORDER BY DESCR 80009 74932 80009 334 3379 04 535027 119 3358 00 TK0435 ORDER BY DESCR 78189 211 041800 00 78189 211 041800 00 80009 342 0860 00 TK0858 211 0244 00 80009 DM 5102 DM 5520 Service Manual 441 1910 00 Fig 1 Power Supply Exploded View DM 5120 5520 Service Manual gt w w Fig 2 Rear Panel Assembly DM 5120 5520 Service Manual S Fig 3 Chassis Assembly DM 5120 5520 Service Manual LATCH RETAINING NOTE ORIENTATION ul BAR LATCH RELEASE KNOB LATCH 2 2 lt 3 5120 5520 Service Manual Fig 5 Analog Board Assembly DM 5120 5520 Service Manual MANUAL CHANGE INFORMATION At Tektronix we continually strive to keep up with latest electronic developments by adding circuit and component improvements to our instruments as soon as they are d
32. 120 5520 Service anual Ekt Board Assy Display Board kt Board fissyzDigital Board Ckt Board Assy Analog Board Keithley 5120 110 Keithley 5120 100 Keithley 5120 120 Replaceable Electrical Parts Al A1C1030 A1C2020 A1C2050 A1C3010 A1C3060 A1C4011 A1C4021 104030 A1C4060 1 5010 1 5030 1 5050 A1CR3031 A1CR3070 A1CR4010 A1CR4012 A1CR4020 A1CR4070 A1J1040 A1J1070 1 1071 A1J1072 A1J2020 A1J3060 A1Q2070 A1Q3070 A1Q5040 A1R3030 A1R3031 A1R4040 1 5030 185031 A1R5033 A1R5034 1 5030 2 A2J1010 A2J1110 F100 FL100 T100 W100 Tektronix t No Part No 671 1237 00 281 0774 00 281 0774 00 281 0774 00 281 0774 00 281 0774 00 281 0774 00 281 0774 00 290 1186 00 90 1186 00 290 1187 00 281 0774 00 281 0774 00 152 0488 00 152 0198 00 152 0198 00 152 0198 00 152 0198 00 152 0198 00 131 2484 00 131 1078 00 131 1078 00 131 1078 00 131 2527 00 131 2789 00 151 0918 00 151 0917 00 151 0917 00 303 0202 00 303 0202 00 308 0252 00 303 0511 00 131 0566 00 131 0566 00 131 0566 00 152 0512 00 571 1266 00 131 2542 00 131 1789 00 159 0016 00 119 3436 00 120 1772 00 196 3196 00 Serial Asserbiy Effective Dscont POWER SUPPLY HEr amp Description CIRCUIT 80 ASSY POWER SUPPLY 80009 DI 0 022MFD 20 1000 04222 CAP FXD CER DI 0 022MFD 20 amp 100V 04222 CAP FXD CER 01 0 022 0 20 100 04222 F
33. 120 5520 Service Manual Maintenance 4 Carefully move the Display board away from the front frame to clear the push buttons and remove the Display board from the instrument 5 Reassemble in reverse order Digital Board Assembly A20 Removal 1 Remove side panels 2 Unplug five connectors from the top of the Digi tal board two from the front panel and two from the rear panel and one from the Analog board 3 Lay the instrument on its right side with the bot tom facing you 4 Remove the five screws holding the Digital board to the bottom frame assembly Hold the board as you remove the last screw to prevent the board from slipping 5 Carefully lift the Digital board straight up and out of the instrument 6 Reassemble in reverse order Analog Board Assembly A30 Removal 1 Remove side panels 2 Unplug from the Analog board the five wires at tached to the input connectors 3 Unplug from the Digital board the 8 wire connec tor coming from the Analog board 4 Lay the instrument on its right side with the top facing you 5 Remove the five flat head screws holding the Analog board to the top frame assembly 6 Carefully lift the Analog board out of the instrument 7 The Analog board can be completely exposed by removing the four screws holding the Analog board between the two shields 8 Reassemble in reverse order 4 5 Maintenance Troubleshooting The troubleshooting information contained
34. 1593 02 37 129 0160 00 38 348 0640 00 39 214 3026 00 40 334 3379 04 41 348 0430 00 42 119 3358 00 43 211 0025 00 44 210 0586 00 45 210 0586 00 46 342 0860 00 47 211 0244 00 48 441 1910 00 Serial Assembly No Effective Dscont 1 6 23100101 gt jd CD CS Rem rN A w POWER SUPPLY 12345 Name amp Description FRAME PNL CAB ATTACHING PARTS SCREW MACHINE 6 32 X 0 188 STL END ATTACHING PARTS SPACER MTG 7 8 L X 0 7 W X 0 063 THK ATTACHING PARTS SCREW TPG TF 4 40 X 0 25 TYPE C FLH 100 DEG END ATTACHING PARTS MARKER IDENT MKD DM5520 MARKER IDENT MARKED TEKTRONIX HANDLE FOOT HANDLE NON SKID HANDLE GRIP LEXAN ATTACHING PARTS SCREW MACHINE 6 32 X 1 0 FILLISTER HEAD END ATTACHING PARTS ARM PIVOT HANDLE ATTACHING PARTS SCREW TPG TF 8 16 X 0 562 L PLASTITE END ATTACHING PARTS BUMPER PLASTIC BLACK POLYURETHANE COVER PLUG IN POWER SUPPLY ALUMINUM ATTACHINAG PARTS SCREW MACHINE 6 32 X 0 250 PNH STL SCREW MACHINE 8 32 X 0 375 PNH STL END ATTACHING PARTS TRANSFORMER PWR SEE T100 REPL ATTACHING PARTS NUT PL ASSEM WA 4 40 X 0 25 STL CD PL END ATTACHING PARTS SCREW MACHINE 10 32 X 2 25 HEX HD STL WASHER FLAT 0 204 ID X 0 438 00 X 0 032 STL WASHER FLAT 0 188 ID X 0 375 OD X 0 31 INSUL SLVG ELEC 0 187 ID X 1 5 L MYLAR BRACKET CLAMP TRANSISTOR ATTA
35. 17 B1 2C R28C B6 3C C31 B1 2D R29 A6 4C C40 D6 2D R30 A6 4D C41 D4 2D R31 D7 2D C42 D6 2D R32 D4 2D C43 D4 2D R33 C6 2D C44 D2 2C R34 B5 2D C45 C2 2C R35 B1 2D C46 Ci 2D R53 C8 4B C47 B2 2D R67 4B C48 D4 20 R68 B7 4C C49 C4 2D R69 B7 4B C54 D4 2D R70 C7 4B C55 D4 2D R71 B3 2E R72 C2 2C CR2 C4 2D R73 B1 2D CR3 B4 2D CR6 A8 4D U3A A8 4C 7 7 D U3B B8 4 CR8 B5 2D U3B C8 4C CR9 B5 2D U3C B8 4C CR10 C5 2D U21A C3 2D CR11 C6 2D U21B C3 2D CR12 B3 2C U21C C3 2D U21D B2 2D K4 07 20 U23A 7 2 K5 5 2D U23B C4 2D U23C 05 20 026 B7 4C U23D D7 2D Q28 B7 4C U26A CS 2D C7 4 U26B 20 036 C7 4C U27 D2 2C Q37 B7 4C U28A B4 2D Q38 B7 4C U288 B1 2D Q39 7 40 U42A B3 3C Q40 A7 4D U43D D8 3B R24 D4 2D VR2 C8 48 5120 5520 Service Manual dcc B pp O 150 15 200 8 300 8 DO INSERT 15 151 2 RELAY f p C4 ACY INPUT 3 E ua SR C NOT INSERT I 15U i 15 O Nt 150 1350 C15 H C14 D 0 1UF 0 1UF 211 UES fa U26B 2 15U 15U U26A 1 LF353 2353 2 Su 159 154 154 150 s Vet js IT 2 s E gt 12 SU 10 ee 11 T 8 5 He W 5 XI DAC
36. 4E U21 B5 4D F2 C8 4E U22 C5 4D F3 D7 4E U23 B5 4D DM 5120 5520 Service Manual C am yan mal eun z 3 I 8 ay idi 116 167366 55 4 C20 I Ca pes LOUF 2200 0 306 5 2 Bu FROM F15 5U ANA 116 pi a lt t of d 3256 U23 Saudi 1 2HM1 3 e 1 150 GMD 16 HC18 a 41215 V 1 GHQLF GND 10uF or 15u 79915 1 DM5120 5520 UN c nee nem 50 359 ANA 5500 ISOLATION 59 AT STROBE IN 24 gt E HCT04 gt H 11 SU ANA 50 J15 04 2 ps CLOCK IH KS 279 Ue 14 415 Bar rV COUNTS BACK 2 2 74 A D COUNTS 2 Ces C24 330PF 3z0PF 14 Qr DO 50 L OPTO ISO0LARTORS 4 lt 24 HCT04 2 COMPONENT NUMBER EXAMPLE Component Number A23 A2 R1234 i Sele malic Sunara __ Number Chasse pone nts kawa Humber mrhr sm End
37. 5 to 19 0015 300 kQ B 190 000 189 958 to 190 042 3 MQ 1 90000 1 89958 to 1 90042 30 MQ _ 19 0000 18 9808 to 19 0192 300 B 100 000 97 998 to 102 002 A Four Wire Configuration 300 Ohm to 30 k Ohm Ranges OUTPUT Hi RESISTANCE CALIBRATOR MODEL 5450A B Two Wire Configuration 300 k Ohm to 300 M Ohm Ranges OUTPUT Hi RESISTANCE CALIBRATOR MODEL 5450A OUTPUT LO Fig 2 3 Connections for Ohms Check DM 5120 5520 Service Manual 4 Check DC Current Test Equipment Required Current Calibrator DC Voltage Calibrator Standard Test Leads CAUTION Do not exceed 3 A to the AMPS and LO input terminals the front panel current fuse will blow a Press DMM keys as follows DCA LED on AUTO LED on PROGRAM LED on PROGRAM displayed 2 current digits displayed f or to display 5 1 2d b Connect the DMM to the current calibrator and the DC voltage calibrator as shown in Fig 2 4 c Set the calibrator source to output 300 pA d CHECK the reading is within the limits listed Table 2 5 e Repeat the procedure for the 3 mA 30 mA 300 mA and 3 A ranges by applying the respective DC cur rent levels listed in Table 2 5 DM 5120 5520 Service Manual Performance Check CURRENT LO DC VOLTAGE MODEL 5440A CALIBRATOR 2 CALIBRATOR MODEL 2500E Fig 2 4 Connections for DC Current Check f CHECK reading for each range is within the li
38. 8A D8 30 VR4 A7 3D R38B C8 3D DM 5120 5520 Service Manual INPUT BUFFER as 15U 9 DM5120 5520 C R D INPUT 159 15U 5 3806 C25 0 1UF C26 0 1UF 15 P15 P15 P1S P15 15 GEER FETE FEE HEGE EEG J Peg 44 20 20 J P20 J P20 J P20 J P20 1 3 5 6 8 150 150 E 50 I 60 250UF 5 R108 6 49K R36 Y 45 9K t gt REF 2 R37 R10 2 14 3K 1 8 5 o o REFERENCE ja ju jo a 2 COMPONENT NUMBER EXAMPLE Clussis maunttd components have as Acsem hy Number Pim end of Decincal Parts List Static Sensitive Devices See Mai 230008 300 8 FAST m ZERO 23 ei i gt amp Qo 515 Z FINRL SLOPE lt gt 5 SYNC C Q2 se INT 1M lt Des SENSE LO 100K SENSE I Q 1M 30mA 100K C lt 210 3 8 amp 7 1K 30008 Qu X10AC 3A c ATTEN lt RELAY C se ACY RELAY C ve 16 3U RELAY 15 8 06 13 OHH RELAY I Qc 11 SENSE H 10 NC lt i ve 5 x10 2 AC cs j DCA G ca MUX lt Qs PRE C 1M SENSE C gt
39. A CAL FIRST 300E 3 000 000 mA 000 000 mA CAL LAST 0 DCA RANGE 5 3A 3 00000 A 3000 00 mA CAL FIRST 3 0 00000 A 0000 00 mA CAL LAST 0 3 10 DM 5120 5520 Service Manual 6 Calibrate AC Current a Select ACA function b Select ACA range of 300 pA c Connect the DMM to the AC current calibrator Fig 3 6 d Select Program 36 The display prompts 300 000 pA e Set the AC current calibrator to 300 000 at frequency of 500 Hz Allow a few seconds for the voltage to stabilize f Press the ENTER key The display prompts 030 000 pA Set the AC current calibrator to 030 000 pA at 500 Hz Allow a few seconds for the voltage to stabilize h Press the ENTER key The ACA calibration points are updated stored for the selected range and the ACA function returns to normal Calibration CURRENT LO AC VOLTAGE CALIBRATOR AT MODEL MODEL 2500E Fig 3 6 AC Current Calibration Configuration i Repeat steps d through h for the remaining ACA ranges using Table 3 6 as a guide 7 Disable Calibration Mode After completing calibration press the CAL LOCK switch with a small screwdriver to turn off the CAL LOCK indicators in the display Place a dated calibra tion sticker over the CAL LOCK switch access hole Table 3 6 AC CURRENT CALIBRATION DMM ACA DMM Calibration Current Calibrator IEEE 488 Range Point Output 500 Hz Bus Command ACA RANGE 1 300 300 000 300 000 CA
40. AC calibrator output to 300 mV at 500 Hz Allow few seconds for the voltage to stabilize f Press the ENTER key The display prompts 030 0000 mV g Set the AC calibrator output to 30 000 mV at 500 Hz Allow a few seconds for the resistance to stabilize h Press the ENTER key The ACV calibration points are updated stored for the selected range and the ACV function returns to normal Repeat steps d through h for the remaining ranges using Table 3 4 and Fig 3 3 as a guide NOTE The AC Volts calibration is not complete until step 4 below is performed 4 Check Adjust AC Volts at 70 kHz a Set ACV range to AUTO b Select Program 2 and set digits to 5 1 2 c Set the AC calibrator output to 100 000 V at 70 kHz Allow a few seconds for the voltage to stabilize d CHECK display reading is 100 000 V 1 500 V If it is continue with the next step If not skip to step g e Set the AC calibrator output to 10 0000 V at 70 kHz Allow a few seconds for the voltage to stabilize f CHECK display reading is 10 0000 V 0 1500 If it is the function calibration is complete If not continue with step g 3 8 POWER AC VOLTAGE AMPLIFIER CALIBRATOR MODEL 5200 3 3 Volts Calibration Configuration g Disconnect power to the h Remove the its power module reconnect it through the extender cables listed in Table 3 1 WARNING
41. C S16 B4 4D DS4 D4 3C S17 A4 3E DSS 03 30 056 08 30 88 3C DS7 D8 3D U1B A6 3C 058 D8 OFF BD U1C C7 3C U1D B6 14 A2 4 U1E C6 3C P14 A4 4C U1F B6 3C P14 A6 4C U1G B6 3C S S UE U1H C7 3C ogerce see 090000009 000000000 ed 8 S1 C5 3B U2A C6 3D 1 265 464 1451 52 5 3C U2B C6 3D bd PR S3 C4 3C U2C 5 3 Boooooooo ed ef 64 C4 3C U2D C5 3D an 55 B5 3C U2E C4 3D S6 B5 3D U2F C4 3D 57 B4 3D U2G C3 3D S8 B4 30 U2H C3 3D S9 B5 48 U4 B7 3D S10 B5 4C US B7 35 9000000000090 Fig 7 1 A10 Display Circuit Board Assembly DM 5120 5520 Service Manual NOTE 058 15 INSERTED DS8 NJ DS7 REM Os 056 ADDRESSED AP z 10 e ENE 5 5 G DM5120 5520 3 1 1 1 4 1 9 c dp dp dp 8 P P P P h h h 14 h m m m m d d d d b b b 10 e 1 n n 13 n 8 q 115 9 a a 12 k k k 5 k j 6 J U1 COMPONENT NUMBER EXAMPLE Chastt meunted compenents have no Number 56E end of Replacestte Electrical Parts List Static Sensitive Devices See Maintenance Section 12 19 14 12 21 24 16 11 PROGRAM ICAL LOCK C1 0 1UF NOTES 1 RLL PUSHBUTTONS SWITCHES ARE SHOWN IN THE 10 4 B 26 los gt PUSHBUTTON OUT POSITION
42. CHING PARTS SCREW MACHINE 4 40 X 0 375 PNH STL SCREW MACHINE 4 40 X 0 375 100 DEG STL END ATTACHING PARTS CIRCUIT BD ASSY GPIB CONN SEE 2 REPL TERMINAL LUG 0 146 ID LOCKING TIN PL NUT PL ASSEM WA 4 40 X 0 25 STL CD PL HARDMARE KIT JACKSOCKET FOR GPIB PLATE ADAPTER ALUMI NUM CA 55 SP ELEC 20 COND 12 4 L RIBBON ATTACHING PARTS SCREW SHOULDER 2 56 X 0 54 STL NUT PLAIN HEX 2 56 X 0 188 BRS CD PL WASHER LOCK 4 SPLIT 0 025 THK STL WASHER FLAT 0 093 ID X 0 281 OD X 0 02 STL END ATTACHING PARTS CIRCUIT BD ASSY PWR SPLY SEE Al REPL ATTACHING PARTS SCREW MACHINE 4 40 X 0 25 PNH STL END ATTACHING PARTS CIRCUIT BD ASSY INCLUDES KEY CONN PLZN CKT BOARD CONN SPACER POST 0 25 L 4 40 THRU BRS GROMMET PLASTIC BLACK ROUND 0 188 ID SPRING GROUND CU MARKER IDENT MKD GROUND SYMBOL 12 BUMPER PLASTIC BLACK POLYURETHANE FUSE DRAWER VOLTAGE SELECTOR SCREW MACHINE 4 40 X 0 375 FLH 100 DEG STL NUT PL ASSEM 4 40 X 0 25 STL CD PL NUT PL ASSEM WA 4 40 X 0 25 STL CD PL INSULATOR XSTR POLYSULFONE BLACK OR NATURAL SCR ASSEM WSHR 4 40 X 0 312 PNH STL CHAS PWR SUPPLY ALUMINUM ADDED JUN 1989 Code 80003 93907 80009 83385 80009 80009 80009 80009 80009 80009 93907 74932 80009 Mfr Part No 426 2289 00 ORDER BY DESCR 361 1507 00 ORDER BY DESCR 334 7564 00 334 7342 00 348 1068 00 367 0398 00 211 0467 00 367 0397 00 225 38131
43. DE Function Input amp Measurement Buffer Relays Range Switches Multiplex Range Phase Mode Gain Closed Closed Switches Closed 300 Q SENSE LO 01 X10 K2 K3 Q11 U22D U24D U22B Q32 REF HI 02 X1 K2 K3 Q11 U22D U24D Q35 Q12 REF LO 03 X1 K2 K3 Q11 U22D U24D U25A Q32 SENSE HI 04 X10 K2 Q11 U22D U24D Q30 3K SENSELO 01 X1 K2 K3 Q11 U22D U24D 0228 032 REF HI 02 X1 K2 011 U22D 0240 035 012 REF LO 03 X1 K2 K3 Q11 U22D U24D U25A Q32 SENSE HI 04 X1 K2 K3 Q11 U22D U24D Q30 30 K SENSELO 01 X1 K2 K3 Q11 U22C U24A U22B Q32 REF 02 X1 K2 K3 Q11 U22C U24A Q35 Q12 REF LO 03 X1 K2 K3 Q11 U22C U24A U25A Q32 SENSE HI 04 X1 K2 K3 Q11 U22C U24A Q30 300 K SENSE LO 01 X1 K2 K3 Q12 Q3 U22C U24A U22B Q32 REF 02 X1 K2 K3 Q12 Q3 U22C U24A Q35 REF LO 03 X1 K2 K3 Q12 U22C U24A Q34 SENSE HI 04 X1 K2 K3 Q12 Q3 U22C U24A Q30 3M SENSE LO 01 X1 K2 K3 Q12 Q13 U22C U24A U22B Q32 REF HI 02 X1 K2 K3 Q12 Q13 U22C U24A Q35 REF LO 03 X1 K2 K3 Q12 Q13 U22C U24A Q34 SENSE HI 04 X1 K2 K3 Q12 013 U22C U24A Q30 30 M SENSELO 01 X1 K2 Q12 U22C U24A U22B Q32 REF HI 02 X1 K2 Q12 U22C U24A Q35 SENSE HI 03 X1 K2 Q12 U22C U24A Q30 No Test 04 300 M SENSE LO 01 X1 K2 Q12 U22C U24A U22B Q32 REF 02 X1 K2 Q12 U22C U24A Q35 SENSE HI 03 X1 K2 Q12 U22C U24A Q30 No Test 04 300 pA DC SIG ZERO 01 X10 U23A U25D 032 CAL ZERO 02 X1
44. L FIRST 300E 6 030 000 pA 030 000 pA CAL LAST 30E 6 ACA RANGE 2 3 mA 3 00000 mA 3 00000 mA CAL FIRST 3E 3 0 30000 mA 0 30000 mA CAL LAST 300E 6 ACA RANGE 3 30 mA 30 0000 mA 30 0000 mA CAL FIRST 30E 3 03 0000 mA 03 0000 mA CAL LAST 3E 3 ACA RANGE 4 300 mA 300 000 mA 300 000 mA CAL FIRST 300E 3 030 000 mA 030 000 mA CAL LAST 30E 3 ACA RANGE 5 3 00000 3000 00 mA CAL FIRST 3 0 30000 0300 00 mA CAL LAST 300E 3 DM 5120 5520 Service Manual z a Section 4 MAINTENANCE General Information Introduction This section of the manual provides maintenance in structions and serving information for the DM 5120 and the DM 5520 and power module Dangerous potentials exist at several points throughout the instrument and power module When the power module must be operated with the cabinet removed do not touch exposed connections or components Disconnect power before cabinet removal cleaning or replacing parts Static Sensitive Components Static discharge may damage semiconductor components in this instrument This instrument contains electrical components that are susceptible to damage from static discharge See Table 5 1 for relative susceptibility of various classes of semiconductors Static voltages of 1 kV to 30 kV are common in unprotected environments Observe the following precautions to avoid damage 1 Minimize handling of static sensitive components 2 Transport and store stati
45. MENT 4 6 iv DM 5120 5520 Service Manual OPERATORS SAFETY SUMMARY The general safety information in this part of the sum mary is for both operating and servicing personnel Specific warnings and cautions will be found through out the manual where they apply but may not appear in this summary Safety information applies to both the DM 5120 and DM 5520 unless noted otherwise TERMS In This Manual CAUTION statements identify conditions or practices that could result in damage to the equipment or other property WARNING statements identify conditions or practices that could result in personal injury or loss of life As Marked on Equipment CAUTION indicates a personal injury hazard not im mediately accessible as one reads the marking or a hazard to property including the equipment itself DANGER indicates a personal injury hazard immedi ately accessible as one reads the marking SYMBOLS In This Manual A This symbol indicates where applicable cautionary or other information is to be found As Marked on Equipment DANGER High voltage Protective ground earth terminal A ATTENTION refer to manual Power Souce This product is intended to operate from a power module connected to a power source DM 5120 or from a power source DM 5520 that will not apply more than 250 volts rms between the supply con ductors or between either supply conductor and DM 5120 5520 Service
46. Manual ground A protective ground connection by way of the grounding conductor in the power cord is essen tial for safe operation Grounding the Product This product is grounded through the grounding con ductor of the power module power cord To avoid electrical shock plug the power cord into a proper wired receptacle before connecting to the product input or output terminals A protective ground con nection by way of the grounding conductor in the power module power cord is essential for safe operation Danger Arising from Loss of Ground Upon loss of the protective ground connection all accessible conductive parts can render an electric shock Use the Proper Power Cord DM 5520 Use only the power cord and connector specified for your product Use only a power cord that is in good condition See Operating Instructions section of the Instruction Manual for power cord configuration Refer cord and connector changes to qualified service pesonnel Use the Proper Fuse To avoid fire hazard use only the fuse of correct type voltage rating and current rating as specified in the parts list of this manual Refer fuse replacement to qualified service personnel Do Not Operate in Explosive Atmospheres To avoid explosion do not operate this product in an explosive atmosphere unless it has been specifi cally certified for such operation Do Not Operate Without Covers To avoid personal injury do not ope
47. NPUT O R11C Q17 N V R11D OX O TO T102 FINAL SLOPE COMPARATOR FEEDBACK CONTROL CIRCUIT DUTY CYCLE COMPARATOR 5 v R9C R9B V Fig 1 6 A D Converter Simplified Schematic 3 84 MHz clock and counted Once the comparator output goes low the VIA stops counting and the reading can be computed Control Circuitry The signals for the circuitry that provides control of the various FETs relays analog switches and logic levels are supplied by the shift store registers U29 U30 U31 and U32 see diagram 6 CLOCK DATA and STROBE signals are sent from the VIA U109 across the opto isolators AT1 and AT3 see diagram 3 The opto isolators transformers provide 350 V isolation between the analog and digital sections of the instrument DATA is ser ally loaded into the shift store registers and a STROBE pulse causes the registers to simultaneously output the appropriate logic levels to the FET analog switch and relay drivers Digital Circuitry The DM 5120 5520 is controlled by an internal micro computer This section briefly describes the opera tion of the microcomputer and associated digital circuitry Refer to diagrams 2 and 3 for circuit details Microcomputer Diagram 2 The microcomputer centers around the 8 bit 68B09 microprocessor U10 The MPU has direct control over the display front panel switches A D converter IEEE 488 bus as well as the READING COMPLETE Output and
48. ORDERING INFORMATION Replacement parts are available from or through your tocal Tektronix Inc Field Office or representative Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest circuit improvements developed in our engineering department It is therefore impor tant when ordering parts to include the following information in your order Part number instrument type or number serial number and modification number if applicable If a part you have ordered has been replaced with a new or improved part your local Tektronix Inc Field Officeorrepresen tative will contact you concerning any change in part number Change information if any is located at the rear of this manuali LIST OF ASSEMBLIES A list of assemblies can be found at the beginning of the Electrical Parts List The assemblies are listed in numerical order When the complete component number of a part is known this list will identify the assembly in which the part is located CROSS INDEX MFR CODE NUMBER TO MANUFACTURER The Mfr Code Number to Manufacturer index for the Electrical Parts List is located immediately after this page The Cross Index provides codes names and addresses of manufac turers of components listed in the Electrica Parts List ABBREVIATIONS Abbreviations conform to American National Standard Y 1 1 COMPONENT NUMBER column one of the
49. PT ELEC CKT 80 24 CONTACT RIGHT 00779 CONN ROPT ELEC RTANG 2 10 0 025 SQ PINS 22526 FUSE CARTRIOGE 3A6 1 5 250V FAST BLOW 71400 FILTER ELEK LINE FILTER W AC CONN ON 80009 TRANSFORMER PWR 75498 LEAD ELECTRICAL 18 AWG 2 0 L 5 4 80009 ADDED JUN 1989 Code Mfr Part No 671 1237 00 2012223 MA201E223MAA 201 223 201 223 2016223 MA201E223MAA 201 223 810472 050 05 810472 050 05 81D183MO16KD5 MA201E223MAA MA201E222MAA 152 0488 00 1N5624 1N5624 1N5624 1NS624 145624 09 61 1081 303 056 520 301 303 056 520 301 303 055 520 301 3107 11 207 01 09 61 1045 151 0918 00 151 0917 00 151 0917 00 GB 2025 G8 2025 12405 390 5 685115 07 07 07 78709 671 1266 00 552791 2 65268 008 AGC C4 1 1 2 119 3436 00 128 7065 196 3196 00 5120 5520 Service Manual Section 7 DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS Symbols Graphic symbols and class designation letters are based on ANSI Standard 32 2 1975 Logic symbology is based on ANSI Y32 14 1973 terms positive logic Logic symbols the logic function performed and may differ from the manufac turer s data The overline on a signal name indicates that the signal performs its intended function when it is in the low state Abbreviations are based on ANSI Y1 1 1972 Other ANSI standards that are used in the preparation of diagrams by Tektronix In
50. See Section 2 of the Instruction Manual for clarification of the VsHz specification DM 5120 5520 Service Manual 2 3 Pertormance Check 3 Check Ohms Test Equipment Required Resistance Calibrator Kelvin Test Leads CAUTION Do not exceed 300 V RMS 425 V peak between the input and LO terminals or instrument damage may occur a Press DMM keys as follows LED on AUTO LED on PROGRAM LED on PROGRAM displayed 2 current digits displayed f or to display 5 1 2d b Connect the DMM to the resistance calibrator as shown in Fig 2 3 c Set the calibrator to the SHORT position and enable NULL on the DMM f CHECK the display reads 000 000 g Set the calibrator to output 190 0 h CHECK the reading is within the limits listed in Table 2 4 i Disable NULL and leave it disabled for the remainder of this check j Connecting the DMM and resistance calibrator as shown in Fig 2 3 check the 3 through 300 ranges by applying the respective resistance levels listed in Table 2 4 k CHECK the readings are within the limits listed in Table 2 4 ed 3 p X gt i p 5 1 3S yg 20 C 2 4 LIMITS FOR OHMS CHECK DMM N Fig 2 3 Applied Range Up Resistance Reading Limits 18 C to 28 C 300 Q A 190 000 Q 189 979 to 190 021 kn A 1 90000 1 89985 to 1 90015 30 19 0000 18 998
51. Tektronix COMMITTED TO EXCELLENCE WARNING The following servicing instructions are for use by qualified personnel To avoid personal injury do not perform any servicing other than that contained in operating instructions unless you are qualified to do so Refer to the Operators Safety Summary and Service Safety Summary prior to performing any service PLEASE CHECK FOR CHANGE INFORMATION AT THE REAR THIS MANUAL DM 5120 5520 Programmable Digital Multimeter Tektronix Inc P O Box 500 Beaverton Oregon 97077 Serial Number 070 7319 00 First Printing OCT 1988 Product Group 76 Revised JUN 1989 Copyright 1988 Tektronix Inc All rights reserved Contents of this publication may not be reproduced in any form without the written permission of Tektronix Inc Products of Tektronix Inc and its subsidiaries are covered by U S and foreign patents and or pending patents TEKTRONIX TEK SCOPE MOBILE and registered trademarks of Tektronix Inc TELEQUIPMENT is a registered trademark of Tektronix U K Limited Printed in U S A Specification and price change privileges are reserved INSTRUMENT SERIAL NUMBERS Each instrument has a serial number on a panel insert tag or stamped on the chassis The first number or letter designates the country of manufacture The last five digits of the serial number are assigned sequentially and are unique to each instrument Those manufactured in the United State
52. X 3608 9301 ALLEN DR 111 INDUSTRIAL RD ST CHARLES ROAD 14150 SW KARL BRAUN DR PO BOX 500 345 SWIFT AVE 3221 W BIG BEAVER RD 701 SONORA AVE 600 18TH AVE 4300 S RACINE AVE 810 SE SHERMAN 1116 W ISABEL ST 28775 AURORA ROAD REV JUN 1989 Code Manufacturer Address City State Zip Code HARRISBURG PA 17105 CLEVELAND OH 44125 4632 COLD SPRING 41076 9749 WARREN MI 48091 ELGIN IL 60120 BEAVERTON OR 97077 0001 SOUTH SAN FRANCISCO CA 94080 6206 TROY MI 48098 GLENDALE CA 91201 2431 ROCKFORD IL 61108 5181 CHICAGO IL 60609 3320 PORTLAND OR 97214 BURBANK CA 91506 CLEVELAND OH 44139 DM 5102 DM 5520 Service Manual FIG 8 INDEX HO Mm ce Ger s s 1 1 1 2 1 3 1 4 1 3 1 6 TEKTRONIX ALAN _ 070 728 070 731 7 070 7318 xx 105 0865 00 105 0865 00 rder by desc 159 0015 00 211 0062 00 211 0541 00 213 0568 00 214 1061 00 214 3089 00 214 3143 00 220 0633 00 260 2455 00 260 2454 01 357 2665 00 3557 3534 1 337 353 060 555 0170 00 361 1516 00 366 1851 01 386 3657 01 426 2301 00 426 2303 00 CIRCUIT BOARDS 5120 5520 Service Manual SERIAL SERIAL MO QTY EFFECTIVE 501 w r gt m3 f r amp DESCRIPTION Leads Meter not shoun Instruction not shoun Instrusent I F Guide not shown Reference Guide
53. XD CER DI 0 022MFD 20 100V 04222 CAP FXD CER 01 0 022 0 20 100 04222 CAP CER DI 0 022MFD 20 100V 04222 DI 0 022MFO 20 100V 04222 CAP ELCTLT 47000 20 SOWVDC 56289 ELCTLT 4700UF 20 50 56289 CAP ELCTLT 18000UF 20 16WVDC 56289 DI 0 022MFD 20 100V 04222 CAP FXD CER DI 0 022MFD 204 100V 04222 SEMICOND DVC DI B8RIOGE SI 200V 1 5A 80009 SEMICOND 01 51 2007 249 03508 SEMICOND DVC DI RECT SI 200V 249 03508 SEMICOND DVC OI RECT SI 200V 3A A249 03508 SEMICONO DVC DI RECT SI 200V A249 03508 SEMICOND OVC DI RECT SI 200V 249 03508 TERM SET PIN 8 PIN INSULATED 27264 CONN RCPT ELEC CKT 80 28 56 CONTACT 31781 CONN RCPT ELEC CKT BD 28 56 CONTACT 31781 CONM RCPT ELEC CKT 80 28 56 CONTACT 31781 TERM SET PIN HEADER 1 X 7 0 156 CTR 26742 CONN RCPT ELEC HEADER I X 4 0 156 SPACING 27254 TRANSISTOR PNP 15 80 80009 TRANSISTOR NPN POWER 15A 80V 80009 TRANSISTOR NPN POWER 15A 80V 80009 RES FXD CMPSN 2K OHM 5 1W 01121 RES FXD CMPSN 2K OHM 54 1W 01121 RES Ww 390 OHM 5 3W 00213 RES CMPSN 510 OHM 5 IW 01121 BUS CONDUCTOR DUMMY RES 0 094 OD X 0 225 L 24546 BUS CONDUCTOR DLMMY RES 0 094 00 X 0 225 24546 BUS CONDUCTOR DUMMY RES 0 094 00 X 0 225 24546 SEMICOND OVC DI ZEN SI 9 1V 54 1W 00 41 12969 CIRCUIT BD ASSY GPIB CONNECTOR 80009 CONN RC
54. assis mounted com mts hava ma Assembly Number prelia see end of Replaceable Electrical Parti Lisl ASO GP B CONNECTOR BD INTERFACE CONNECTOR BOARDS TO FROM 417 Section 8 REPLACEABLE MECHANICAL PARTS PARTS ORDERING INFORMATION Replacement parts are available from or through your lo Tektronix Inc Field Office or representative Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest circuit provements developed in our engineering department It is therefore important when ordering parts to include the fol lowing information in your order Part number instrument type or number serial number and modification number if applicable If a part you have ordered has been replaced with a new or improved part your local Tektronix Inc Field Office or representative will contact you concerning any change in part number Change information if any is located at the rear of this manual ITEM NAME in the Parts List an item Name is separated from the description by a colon Because of space limitations an Item Name may sometimes appear as incomplete For fur ther Name identification the U S Federal Cataloging Handbook H6 1 can be utilized where possible FIGURE AND INDEX NUMBERS Items in this section are referenced by figure and index numbers to the illustrations DM
55. ates the serial number at which the part was first used Column four 4 indicatesthe serial number at which the part was removed No serial number entered indicates part is good for all serial numbers NAME amp DESCRIPTION column five of the Electrical Parts List In the Parts List an Name is separated from the description by a colon Because of space limitations an Item Name may sometimes appear as incomplete For further Name identification the U S Federal Cataloging Handbook H6 1 can be utilized where possible MFR CODE column six of the Electrical Parts List Indicates the code number of the actual manufacturer of the part Code to name and address cross reference can be found immediately after this page MFR PART NUMBER column seven of the Electrical Parts List Indicates actual manufacturers part number 6 1 CROSS INDEX HFR TO NANUFRCTURER ai i IL w re MFR NER MATE ROORESS ZIPCODE STRTE CIUHTRY CODE Keithley Keithley Instrument Div 28775 Aurora Road 44139 Cleveland 08 Replaceable Electrical Parts DR 5120 5520 Service Manual HO SERIRL SERIRL PART EFFECTIVE 0150081 MANE amp DESCRIPTION Replaceable Electrical Parts Part n RIO 118 7930 00 420 118 7951 80 150 118 7952 00 5
56. ber of tests on itself Tests are performed on memory ROM RAM and E PROM Whenever of the memory tests fails the instrument will lock up and must be repaired If all the tests pass then the current IEEE address and software revision level of the instrument will be displayed Immediately after turning on the DM 5120 5520 the following sequence will take place 1 A digital check will be performed on the ROM cir cuitry If the test fails the instrument will lock up with the following message displayed 0000000000 Replacing 04 may resolve the problem 2 If the ROM passes a digital self test will then be performed on the RAM circuitry If the RAM test fails the instrument will lock up with the following error message displayed _ Replacing U9 may resolve the problem 3 Finally the E PROM circuitry where the calibration constants IEEE address and line frequency set tings are stored will be checked If this test fails the following message is displayed UNCAL Pressing any front panel key till return the instru ment to normal operation however a complete calibration will have to be performed and the IEEE address and line frequency setting should be checked if the test still fails after calibration try replacing U20 and recalibrating the instrument 4 The instrument will then go to the power up default function Program 33 Self Diagnostic Program This front panel program performs a d
57. c are Assembly Numbers and Grid Coordinates Each assembly in the instrument is assigned an assembly number e g A20 The assembly number appears on the circuit board outline on the diagram inthe title for the circuit board component location illustration and in the lookup table for the schematic diagram and corresponding component locator illustration The Replaceable Electrical Parts listis arranged by assemblies in numerical sequence the components are listed by component number see following illustration for constructing a component number A Function Block Title internal Screwdriver Adjustment Cam Switch Closure Chart Dot indicates switch closure Etched Circuit Board Outlined in Black Refer to Waveform Function Block Outline Test Voltage Heat Sink Board Name P O Part of circuit board a P O AS TIMING BOARD Assembly Number Tektronix Part No COMPONENT NUMBER EXAMPLE for circuit boards DM 5120 5520 Service Manual The information and special symbols below may appear in this manual 14 15 1966 Drafting Practices Y14 2 1973 Line Conventions and Lettering Y10 5 1968 Letter Symbols for Quantities Used in Electrical Science and Electrical Engineering American National Standard Institute 1430 Broadway New York New York 10018 Component Values Electrical components shown on the diagrams are in the following units unless noted oth
58. c sensitive components or assemblies in their original containers on a metal rail or on conductive foam Label any package that contains static sensitive assemblies or components 3 Discharge the static voltage from your body by wearing a grounded wrist strap while handling these components Servicing static sensitive as semblies or components should be performed only at a Static free work station by qualified service personnel 4 Allow nothing capable of generating or holding a static charge on the work station surface DM 5120 5520 Service Manual 5 Keep the component leads shorted together when ever possible 6 Pick up components by the body never by the leads 7 Do not slide the components over any surface 8 Avoid handling components in areas that have a floor or work surface covering capable of generat ing a static charge 9 Use a soldering iron that is connected to earth ground 10 Use only special antistatic suction type or wick type desoldering tools Test Equipment Before using any test equipment to make measure ments on static sensitive components or assemblies be certain that any voltage or current supplied by the test equipment does not exceed the limits of the component to be tested Table 4 1 RELATIVE SUSCEPTIBILITY TO STATIC DISCHARGE DAMAGE Semiconductor Classes Relative Susceptibility Levels MOS CMOS microcircuits or 1 _ discretes or linear microcircuits w
59. dded to the level shift current applied through R11C and R11D or R11C only In this manner the 3 03 V bipolar signal from the buffer amplifier is converted to a unipolar signal that can be integrated The integrator is made up of Q1 U19 and C32 When the input to the integrator is applied the integrator output ramps up until its voltage is slightly higher than the voltage applied to the inverting input of the duty cycle comparator U5A The charge balance current whose duty cycle is proportional to the input is fed back to the integrator input through R8 and Q4 Since the charge balance current is much larger than the sum of the input and level shift currents the integrator output now ramps in the negative direction until of U8B goes low The VIA then counts the total number of pulses that occur during the charge balance phase At the end of the charge balance phase the output of the integrator is resting at some positive voltage Since the integrator output is connected to the non inverting input of the final slope comparator U5B the final slope comparator output remains high until the integrator output ramps in the negative direction During final slope Q4 is turned off and the feedback is fed through U16 back to the integrator input The final slope comparator output is then gated with the 1 5 Theory of Operation U43D 3 84 MHz CLOCK FINAL SLOPE CHARGE CURRENT BALANCE CURRENT R11E I
60. e Since this current is common to both resis tances the value of the unknown resistance can be calculated by measuring the voltage across the refer ence resistor and the voltage across the unknown resistance FRONT PANEL CONNECTOR V OHMS SENSE LO I t I 1 i 1 1 1 i VOHMS SENSE HI i i t t t I I I i 1 i 1 1 1 t 1 i 1 1 1 t 1 1 l 1 Roce V OHMS SENSE HI OHMS SENSE LO V OHMS REF HI V OHMS REF LO Fig 1 2 Input Configuration during 2 and 4 Terminal Resistance Measurement DM 5120 5520 Service Manual The following ohms reference resistors are used see Figure 1 3 300 Q and 3 ranges R26 2 30 range R23 30 300 range R17A paralleled by R17C 100 3 MQ range R17A paralleled R17B 1 30 300 MQ ranges R17C 10 By measuring the four inputs to the A D converter the unknown resistance can be computed by the microprocessor using this equation RnEF VQ SENSE HI SENSE LO NNEE ENE VO REF REF LO 45 12 Theory Operation For the 300 Q range VQ SENSE and VO SENSE LO are actually multiplied by a factor of 10 in the input buffer circuit Protection on th
61. e ohms ranges is accomplished by RT1 Q9 and Q16 For an input voltage applied to the Q input terminals Q9 and Q16 clamp the volt age to the reference resistors to a safe limit RT1 limits the current to Q9 and Q16 The DM 5120 5520 is equipped to make 2 or 4 terminal resistance measurements Generally the 4 terminal measurements should be made on the 300 0 OHMS REF HI TO Q35 OF MULTIPLEXER R26 1 002 k OHMS REFERENCE RESISTORS R17B R17C 1 111 M OHMS 110 95 k OHMS OHMS REF LO TO U24A OF 30 k OHMS MULTIPLEXER OHMS REF LO U24D OF 300 OHMS MULTIPLEXER 3 k OHMS Ps U22D INPUT HI OHMS REF LO TO Q34 OF 300 k OHMS MULTIPLEXER M 300 M OHMS TO Q30 OF MULTIPLEXER 7 OHMS SENSE HI OHMS SENSE LO INPUT LO TO U22B OF MULTIPLEXER R e V OHMS SENSEHI V OHMS SENSE LO R REF V X V OHMS REF HI V OHMS REF LO Fig 1 3 Resistance Measurement Simplified Circuitry DM 5120 5520 Service Manual Theory of Operation range because the relatively large output current can develop a significant voltage across the test leads affecting measurement accuracy Figure 1 2 shows the equivalent circuit of the input circuit Rx is the unknown measured resistance and R1 R2 R3 and R4 represent the test lead resistance R2 and R3 are connected only during 4 terminal measurements When using a 2 terminal configura tion all the current flows through the test leads R1 and R4 If Rx has a low value the a
62. efer to the trouble shooting information in Section 4 Maintenance Environmental Conditions Calibration should be performed under laboratory con ditions having an ambient temperature of 22 24 and a relative humidity of less than 70 Recommended Test Equipment The test equipment listed in Table 3 1 or equivalent is suggested to perform the DM 5120 5520 calibra tion Alternate equipment may be used as long as the accuracy is at least as good as the specifications listed in the table Table 3 1 TEST EQUIPMENT REQUIRED Required for Description Performance Specifications These Adjustments Recommended Power DM 5120 Only Tektronix TM 5003 or Module TM 5006 DC Voltage 300 mV 3 V 30 V 300 V ranges 15 DC Volts Fluke 5440A Calibrator ppm DC Current AC Voltage 300 mV 3 V 30 V ranges 20 Hz 0 1 TRMS Volts Fluke 5200A Calibrator 50 Hz 20 kHz 0 0296 100 kHz 0 33 TRMS AC Current AC Power 300 V range 20 Hz 0 12 50 2 20 TRMS AC Volts Fluke 5215A Amplifier kHz 0 04 100 kHz 0 1 Resistance 300 0 3 ranges 15 ppm 30 Ohms Fluke 5450A Calibrator 32 ppm 300 range 225 ppm Current 300 p 3 A ranges 0 025 DC Current Valhalla 2500E Calibrator TRMS AC Current Coax Cables 2 ea required All checks Tektronix PN 012 0057 01 BNC to dual 2 ea required All checks Tektronix PN 103 0090 00 banana adapter DM 5120 5520 Service Manual 3 1 Calibration Internal Adjustments
63. embly NOTE To disassemble the DM 5120 5520 refer to the following removal procedures and exploded views in the Replaceable Mechanical Parts sec tion at the back of this manual DM 5520 Only Power Module Disassembly Power Module Cabinet Removal Remove the Phillips screw the bottom front edge of the cabinet It is located just to the of the cabinet bottom seam Pull on the two release latch handles to slide the DMM out of the cabinet Before removing the cabinet turn the power switch off and disconnect the line voltage cord Remove any plug in modules and the handle assembly Two screws on each side and two screws on the bottom secure the cabinet to the 620 0046 00 front casting Each guide rail is attached to the front cast ing via a screw Additionally four screws located on the bottom and two screws on the back hold the power supply to the cabinet Remove the screws and slide the power supply assembly out through the front of the cabinet Reinstall the cabinet to protect the in terior from dust and to remove personnel shock hazards Power Module Board Removal 1 Remove the power supply assembly from the power module Refer to Cabinet Removal in this section of the manual for instructions 2 On the power supply assembly remove the screws on each side and on the bottom that secure the series pass transistor clamp Remove the clamps 3 Remove the six screws on the interface connec tor side of
64. erwise Capacitors Values one or greater arein picofarads pF Values less than one are in microfarads uF Resistors Ohms 0 The schematic diagram and circuit board component location illustration have grids A lookup table with the grid coordinates is provided for ease of locating the component Only the components illustrated onthefacing diagram are listed in the lookup table When more than one schematic diagram is used to illustrate the circuitry on a circuit board the circuit board illustration may only appear opposite the first diagram on which it was il lustrated the lookup table will list the diagram number of other diagrams that the circuitry of the circuit board appears on Modified Component Depicted in Grey or With Grey Outline See Parts List Strap or Link Plug to E C Board Box Identifies Panel ontrols Connectors and indicators Coaxial connectors male female Plug Index signifies pin No 1 External Screwdriver Adj Shielding Selected value see Parts List and Maintenance Section for Selection Critena Decoupled or Filtered Voltage Refer to Diagram Number Schematic Name and Number Table 7 1 FRONT PANEL amp DISPLAY gt DISPLAY BOARD ASSEMBLY A10 CIRCUIT SCHEMATIC BOARD CIRCUIT SCHEMATIC BOARD NUMBER LOCATION LOCATION NUMBER LOCATION LOCATION t Ct A6 4D 511 B4 4 C2 A6 4D S12 BS 4C 513 B5 4C DS1 D7 3C 514 5 40 052 06 3 S15 A5 4D 7083 05 3
65. eveloped and tested Sometimes due to printing and shipping requirements we can t get these changes immediately into printed manuals Hence your manual may contain new change information on following pages A single change may affect several sections Since the change information sheets are carried in the manual until all changes are permanently entered some duplication may occur If no such change pages appear following this page your manual is correct as printed NOILVINHOA3NI 39NYHO
66. ion Input amp Measurement Buffer Relays Range Switches Multiplex Range Phase Mode Gain Closed Closed Switches Closed 300 mV SIG NULL 01 X10 K1 Q11 U22A Q34 CAL NULL 02 X1 K1 Q11 U22A U25D Q32 CAL 03 X1 K1 Q11 U22A U25C Q32 SIG 04 X10 K1 Q11 U22A Q30 3 V DC SIG NULL 01 X1 K1 Q11 U22A Q33 CAL NULL 02 1 1 Q11 U22A U25D Q32 CAL 03 X1 K1 Q11 U22A U25C Q32 SIG 04 X1 K1 Q11 U22A Q30 30 V DC SIG NULL 01 X1 Q13 Q11 U22A Q33 CAL NULL 02 X1 Q13 Q11 U22A U25D Q32 CAL 03 X1 Q13 Q11 U22A U25C Q32 SIG 04 X1 Q13 Q11 U22A Q35 300 V DC SIG NULL 01 X1 Q3 Q11 U22A Q34 CAL NULL 02 X1 Q3 Q11 U22A U25D Q32 CAL 03 X1 Q3 Q11 U22A U25C Q32 SIG 04 X1 Q3 Q11 U22A Q35 300 mV AC ZERO 01 X1 K4 K5 U21A U21B U25D Q32 CAL 02 X1 K4 K5 U21A U21B U25C Q32 SIG 03 X1 K4 K5 U21A U21B U25C Q32 No Test 04 3 V AC ZERO 01 X1 K4 K5 U21C U25D Q32 CAL 02 X1 K1 K5 U21C U25C Q32 SIG 03 X1 K1 K5 U21C U25C Q32 No Test 04 30VAC _ ZERO 01 x1 K4 U21A U21B U25D Q32 CAL 02 X1 K4 U21A 0218 U25C Q32 SIG 03 X1 K4 U21A 0218 U25C Q32 No Test 04 300 ZERO 01 X1 K4 U23C U23B U25D Q32 CAL 02 X1 K4 U23C U23B U25C Q32 SIG 03 X1 K4 U23C U23B U25C Q32 No Test 04 a DM 5120 5520 Service Manual 4 7 Maintenance Table 4 3 Cont DM 5120 5520 TROUBLESHOOTING MO
67. isplay test and the same memory tests performed upon power up Also included is a troubleshooting test mode that is designed to switch on various switching FETs and relays to allow signal tracing through the instrument Perform the following procedure to utilize Program 33 1 Press the PROGRAM key and then the 3 and 3 numeric keys The display test is first Segments of the display characters will be sequentially dis played for a short time The front panel LEDs will also be on during this test This test allows the operator to note inoperative display segments or LEDs Self test on the ROM RAM and will then be performed These are the same tests DM 5120 5520 Service Manual Maintenance 3 Using Table 4 3 reference the N mode to the cur rent function and range to determine the proper working status of the listed circuit components run on power up and are explained in detail under Power Up Self Test above The DM 5120 5520 will now go into the trouble shooting mode with the first N mode being dis played as follows N 01 The instrument is still on the same function and range as it was before Program 33 was run 4 To change the N mode use the ENTER button 5 To troubleshoot a difference function and or range exit the program by pressing any front panel key except ENTER select the desired function and or range and again run Program 33 Table 4 3 DM 5120 5520 TROUBLESHOOTING MODE Funct
68. ith MOS inputs Most Sensitive ECL 2 Schottky signal diodes d Schottky TTL 4 High frequency bipolar transistors 5 JFETs 6 Linear microcircuits 7 Low power Schottky TTL 8 TTL Least Sensitive 9 equivalent for levels 1 100 to 500 V 4 500 V 7 400 to 1000 V est 2 200 to 500 V 5 400 to 600 V 8 900 V 3 250 V 6 600 to 800 V 9 1200 V Vottage discharged from 100 pF capacitor through a resistance of 100 ohms 4 1 Maintenance Cleaning Instructions This instrument should be cleaned as often as operat ing conditions require Loose dust accumulated on the outside of the instrument can be removed with a soft cloth or small brush Remove dirt that remains with a soft cloth dampened in a mild detergent an water solution Do not use abrasive cleaners To clean the front panel use freon isopropyl alcohol or denatured ethyl alcohol Do not use petroleum based cleansing agents Do not use air or any solvent to clean the Display front panel board Before using any other type of cleaner consult your Tektronix Service Center or representative The best way to clean the interior is to blow off the accumulated dust with dry low velocity air approxi mately 5 Ib in2 or use a soft brush or cloth dam pened with a mild detergent and water solution Hold the board such that the residue runs away from the connectors Do not scrape or use an eraser to clean the edge connector contracts Abrasive c
69. ithin the limits listed in Table 2 6 Table 2 6 LIMITS FOR TRMS AC CURRENT CHECK Reading Limits DMM Applied 18 to 28 Range AC Current 20 Hz 45 Hz 10 kHz 300 pA 290 000 pA 284 100 287 290 287 290 to to to 295 900 292 710 292 710 3 mA 2 90000 mA 2 84100 2 88160 2 88160 t t t O O 2 95900 2 91840 2 91840 30 mA 29 0000 mA 28 4100 28 8160 28 8160 to to to 29 5900 29 1840 29 1840 ER 300 mA 290 000 mA 284 100 288 160 288 160 to to to 295 900 291 840 291 840 2 90000 2 84100 2 88160 2 88160 to to 2 95900 2 91840 2 91840 DM 5120 5520 Service Manual Section 3 CALIBRATION PROCEDURE Introduction Use this calibration procedure to restore the DM 5120 or DM 5520 to the original performance requirements This procedure need not be performed unless the Performance Check Procedure in Section 2 cannot be completed satisfactorily or the instrument fails to meet the Performance Requirements of the electrical characteristics listed in the Specification section in the DM 5120 5520 Instruction manual Calibration Interval Calibration should be performed at least every 12 months or if the performance check procedures in Section 2 show that the DM 5120 5520 is out of specification Calibration is also recommended follow ing instrument repair or modification If any of the calibration procedures in this section cannot be performed properly r
70. l the T shaped end of handle engages the end of the slider DM 5120 5520 Service Manual Rear Panel Removal 1 2 Remove side covers Unplug the power and GPIB cables from the Digi tal board Remove the four screws holding the rear panel to the top frame assembly Remove the four studs holding the rear pane to the bottom chassis assembly Use a 3 16 hex wrench Remove the rear panel Reassemble in reverse order Front Frame Assembly Removal 1 2 Remove side panels Remove the two release latch handles See removal procedure described above Unplug two cables from the Digital board and five wires from the Analog board Remove the ground post from the lower right corner of the front panel Remove the knurled nut Un screw the ground post by inserting a thin point tool such as a scriber into the wire hole in the ground post shaft and turning it counterclockwise Remove 12 screws 6 on top and 6 on bottom holding the front panel assembly to the top and bottom frame assemblies Remove the front frame assembly Reassemble in reverse order Display Board Assembly A10 Removal NOTE The Display board can be removed by first removing the front frame assembly or by remov ing the Analog board as described below Remove side panels Unplug two cables from the Digita board Remove five screws holding the Display board to the front frame assembly DM 5
71. lean ing can remove the gold plating CAUTION Circuit boards and components must be dry before applying power Obtaining Replacement Parts Electrical and mechanical parts can be obtained through your local Tektronix Field Office or repre sentative However many of the standard electronic components be obtained from a local cial source Before purchasing or ordering parts from a source other than Tektronix check the Replace able Electrical Parts list for the proper value rating tolerance and description Ordering Parts When ordering replacement parts from Tektronix Inc it is important to include all of the following information 1 Instrument type include modification or option numbers 2 Instrument serial number 3 A description of the part if electrical include the component number 4 Tektronix part number Soldering Techniques To avoid electric shock hazard disconnect the instrument from the power source before soldering The reliability and accuracy of this instrument can be maintained only if proper soldering techniques are used when repairing or replacing parts General sol dering techniques which apply to maintenance of any precision electronic equipment should be used when working on this instrument Use only 60 40 rosin core electronic grade solder The choice of soldering iron is determined by the repair to be made When soldering on circuit boards or
72. mV 2 counts NOTE Low measurement techniques should be used when checking the 300 mV DC range Refer to the DM 5020 5520 Instruction Manual for low level measurement considerations e Set the calibrator to output 300 mV f CHECK display reads a value within the limits listed in Table 2 2 g Disable NULL press NULL key to turn off LED and leave it disabled for the remainder or the DCV checks h Check the 3 V 30 V and 300 V ranges by apply ing the respective DC voltage levels listed in Table 2 2 i Repeat steps c thru h while applying negative voltages Table 2 2 LIMITS FOR DC VOLTS CHECK DMM Applied DCV Range DC Voltage Reading Limits 18 to 28 300 mV 300 000 mV 299 974 to 300 026 3 V 3 00000 V 2 99987 to 3 00013 30 V 30 0000 V 29 9973 to 30 0027 300 V 300 000 V 299 970 to 300 030 DM 5120 5520 Service Manual 2 Check TRMS AC Volts Test Equipment Required AC Voltage Calibrator AC Power Amplifier Standard Test Leads CAUTION Do not exceed 300 V RMS 425 V 10 V Hz between the input and LO terminals strument damage may occur a Press DMM keys as follows ACV LED on AUTO LED on NULL LED PROGRAM LED on PROGRAM displayed 2 current digits displayed f to display 5 1 2d b Connect the DMM to the AC voltage calibrator and the power amplifier as shown in Fig 2 2 c Set the calibrator to output 290 mV at a frequency of 2
73. mits listed in Table 2 5 g Repeat the procedure for each of the ranges with negative current levels Table 2 5 LIMITS FOR DC CURRENT CHECK DMM Applied Reading Limits Range DC Current 18 to 28 C 300 pA 300 000 mV A 299 710 to 300 290 3 mA 3 00000 Wma 2 99840 to 3 00160 30 mA 30 0000 Wine 29 9840 to 30 0160 300 mA 300 000 YMA 299 840 to 300 160 3A 3 00000 A 2 99720 to 3 00280 Performance Check 5 Check TRMS AC Current Test Equipment Required Current Calibrator AC Voltage Calibrator Standard Test Leads CAUTION Do not exceed 3 to the AMPS and LO input terminals or the rear panel current fuse will blow a Press DMM keys as follows ACA LED on AUTO LED on NULL LED off PROGRAM LED on PROGRAM displayed 2 current digits displayed to display 5 1 2d b Connect the DMM to the current calibrator and the AC voltage calibrator as shown in Fig 2 5 CURRENT LO AC VOLTAGE CALIBRATOR CALIBRATOR MODEL MODEL 2500E 5200A Fig 2 5 Connections for TRMS AC Current Check 2 6 c Set the calibration source to output 300 at a frequency of 20 Hz d CHECK the reading is within the limits listed in Table 2 6 e Repeat the 300 measurement at the other fre quencies specified in Table 2 6 f Repeat the procedure for the 3 mA 30 mA 300 mA and 3 A ranges by applying the respective AC cur rent levels listed in Table 2 6 g CHECK the reading for each range is w
74. mount of volt age developed across the test leads can be sign fi cant Since the voltage is sensed across the combined resistance of R1 Rx and R4 considerable error can be introduced into the reading To use a 4 terminal connection a second set of leads R2 and R3 are connected to the unknown resistance The amount of current through R2 and R3 is much smaller than the current through R1 and R4 Thus the voltage seen by the instrument is much closer to the actual value across the measured resistance minimizing the error DCA and ACA Diagram 5 The resistor current shunt network R28 is configured so that a full scale current input will result in a 300 mV drop across the network on all current ranges For DCA this voltage is routed to the multiplexer through analog switch U24B diagram 4 For ACA the sig nal is routed through U21D to X10 amplifier U28B The amplifier signal then travels through analog switch U21B and buffer U26B to the TRMS converter The converted dc signal is then routed to the multiplexer Multiplexer Diagram 4 The multiplexer circuitry selects among the various signals that are part of the DM 5120 5520 measure ment cycle and connects them to the input buffer amplifier Figure 1 4 shows a simplified schematic of the multiplexer circuitry Figure 1 5 shows the general switching phases for the various signals During each phase an ntegra tion is performed by the A D converter and the resul tant da
75. nd R37 divide down the 46 95 V value to the final 2 1 V reference voltage Input Buffer Amplifier Diagram 6 The input buffer amplifier provides isolation between the input signal and the A D converter Q41 provides the low noise high impedance FET input for amplifier U35 The amplifier can be configured for X1 or X10 gain with R41 and R42 acting as the feedback net work When X1 gain is selected by the microproces sor feedback is routed through pin 12 of the analog switch U44A At X10 gain feedback is routed through pin 13 of the multiplex switch Amplifier gain con figurations for the various functions and ranges are listed in Table 1 1 DM 5120 5520 Service Manual Theory of Operation Table 1 1 INPUT BUFFER AMPLIFIER U35 GAIN CONFIGURATION u Function Range Gain n 1 DCV 300 mV X10 3 300 V X1 All X1 W 300 W X10 3k 300 MW X1 DCA All X10 ACA All X1 A D Converter Diagram 7 The DM 5120 5520 uses a constant frequency vari able pulse width analog to digital converter A simp lified schematic of the A D converter used in the DM 5120 5520 is shown in Figure 1 6 The charge balance phase begins when the input enable disable line is set high This occurs at the end of a software generated delay period that allows the signal to settle after the appropriate multiplexer FET is turned on Once the input is enabled the signal from the buffer amplifier is a
76. not shown Bar Latch Release Latch Retaining Display LED Fuse Cartridge Screw 2 96 x 5 16 Screw 6 32 0 250 Screu 6 32 x 0 579 Contact Elec Lockout Plug In Spring HL Mut Knurled Post Suitch Pushbutton not shown Suitch PB illuninated not shoun Shield Elec Side not shown Shield Elec Top Center Shield Center Stud Shldr Post Spacer Sleeve Knob Latch Support Plug In Frase Sect Botton L 8 R Frame Sect Right Replaceable Wechanical Parts CODE 80009 80009 Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley Keithley 80009 Keithley Keithley Keithley Keithley Ckt Board Assy Display Board see 10 REPL kt Board fissy Digital Board see 120 REPL kt Board Assy finalog Board see R30 REPL REV JUN 1989 Mfr Part 070 7240 xx 070 7317 xx 070 7318 xx 5120 317 9120 316 00 39 FU B2 3120 325 3120 223 31 20 324 3120 32 3120 319 3120 220 3120 327 54 474 50 47 3120 314 3120 317 3120 311 3120 328 361 1516 00 3120 318 3120 371 3120 310 3120 313 8 5 Replaceable Hechanical Parts FIG 1 TEKTRONIX SERIRL MO SERIAL MO QTY NANE 8 DESCRIPTION W INDEX MO NO EFFECT DISCONT Mfr Part rie r apa an n a
77. oduction 1 1 s 5 Calibrate DC Current 3 10 Overall Functional Description 1 1 Analog Circuitry 1 2 AC ir Dt HUNC 28 Input Signal 1 2 ON Nr DCV Diagram 4 cu 12 Section 4 MAINTENANCE ACV D qan 5 uuu 22 arr 1 2 General Information 4 1 OHMS Diagram 4 1 2 Introd 4 1 DCA and ACA Diagram 5 1 4 Static Sensitive Components 4 1 Multiplexer Diagram 4 1 4 Test Equipment ere 4 1 2 1 V Reference Source Diagram 6 1 4 Cleaning 5 2 2 2 4 2 Input Buffer Amplifier Diagram 6 1 5 Obtaining Replacement Parts 4 2 A D Converter Diagram 7 1 5 Ordering Pans cuui eet 4 2 Control Circuitry 1 6 Soldering 2 2 2 4 2 Digital Circuitry 1 6 uy donc deep reas kas
78. plified Block Diagram DM 5120 5520 Service Manual Theory of Operation Analog Circuitry The detailed circuitry of the DM 5120 5520 analog section is located on diagrams 4 5 6 and 7 Input Signal Conditioning Signal conditioning circuitry modifies the input to signal that is usable by the DM 5120 5520 and ap plies that signal to the multiplexer DCV Diagram 4 Signal conditioning for the 30 V and 300 V ranges is performed by resistor divider network R17 On these ranges K1 and K2 are open and the divider network is connected to signal ground through Q11 and U22A The following attenuation of the input sig nal is provided Divided by 10 on the 30 V range Divided by 100 on the 300 V range On the 30 V range Q13 is on and Q3 is off routing the input signal in the multiplexer Q35 On the 300 V range Q13 is off and Q3 is on routing the input sig nal to the multiplexer Q35 On the 300 mV and 3 V ranges the input signal is removed from the resistor divider network Q13 and Q3 off and applies direct ly to the multiplexer through K1 and R13 ACV Diagram 5 The basic steps involved in ACV conditioning are as follows 1 Relay K4 applies the ACV input to the gain cir cuitry Here the signal undergoes a gain factor of 10 800 mV range 1 8 V range 1 10 30 V range or 1 100 300 V range 2 The signal is then applied to the TRMS converter U27 where the ac signal is converted to a dc signal 3
79. ply 018 pin 3 5 5 V 6 15 V Analog Supply 022 pin 3 5 5 V Referenced to analog common Referenced to analog common Referenced to analog common 7 15 V Analog Supplies U21 15 V 15 V 0 75 V pin 3 U23 pin 3 4 10 DM 5120 5520 Service Manual Maintenance Table 4 5 DIGITAL CIRCUITRY CHECKS Step Item Component Required Condition Remarks 1 U4 U9 U20 Pass RAM ROM Display will lock if failure self test on power up occurs 2 U8 pin 2 PAO TTL level pulses every 1 ms VIA clock 3 U8 pin 2 PA1 TTL level pulses every 15 ms Data 4 108 6 PA4 Switch data 5 V or 0 V Data input to VIA 5 U8 pin 7 PA5 Switch data 45 V or OV Data input to VIA 6 U8 pin 8 PA6 Switch data 5 V or Data input to VIA 7 UB pin 7 Switch data 45 V or OV Data input to VIA 8 08 pin 19 Variable pulse train 0 V to 5 V VIA Data Line 9 AT1 pin 6 Variable pulse train 0 V to 5 V Data output 10 U43 pin 13 Variable pulse train 0 V to 5 V Output of A D converter 11 U8 pins 12 thru 16 Variable pusle train 0 V to 5 V Analog data to VIA 12 010 pin 3 1 kHz pulses IRQ line 13 010 pin 37 5 V 5 Reset line 14 U5 ping 45 V signal pulsed 0 V to 5 V INT line every 1 ms 15 U5 pin 19 45 V Logic 1 RESET line 16 U5 pin 18 2 MHz square wave at Clock to 45 V 17 05 pin 28 Should go false 5 V when ATN line command is sent Handshake sequence 18 U5 pins 28 24
80. r on the right side of the DMM as you face the front of the unit Three fuses are located toward the rear of the ex posed circuit board mounted in fuse holders To remove a fuse carefully pull it out of the fuse holder Correct fuse values are marked on the circuit board Replacement fuses are 1 A 250 V 3 AG fast blow Tektronix Part No 159 0019 00 3 8 250 V 3 AG slow blow Tektronix Part No 159 0200 00 After fuse replacement re install the side cover Release Latch Handle and Slider Removal All plastic parts of the latch assemblies and the return springs are individually replaceable However if a latch tension spring becomes damaged the bottom frame rail assembly that it is attached to must be replaced 1 Remove the side panel from the DM 5120 5520 2 Pull the release latch handle out about 1 8 and hold 3 Using a small screwdriver move the release latch slider forward slightly while pushing down on the release latch handle to free the handle shaft from the slider Pull out on handle to remove 4 To repair the release latch assembly remove the bottom rail that it is fastened to The rails are held with screws into the front and rear panel assemblies and the Digital board 5 To replace the release latch handle push the handle shaft through slot in the front panel as far as it will go and hold it Using a small screwdriver move the release latch slider forward and the han dle upward unti
81. r or internal adjustment If the instrument fails to meet these performance checks a qualified service person should perform the internal adjustment procedure in Section 3 and repeat the Performance Check Procedure readjustment does not correct the discrepancy circuit troubleshoot ing is needed NOTE If the instrument performance falls outside the specified range and it is still under warranty contact Tektronix Inc Services Available Tektronix Inc provides complete instrument repair and adjustment at local field service centers and at the factory service center Contact your local Tektronix field office or representative for further information Environmental Conditions All performance checks should be made at 18 28 65 82 F and at less than 75 relative humidity The DM 5120 5520 must be turned on and allowed to warm up for at least two hours before beginning the performance checks If the instrument has been subject to extremes of temperature outside the range specified above additional time should be allowed for internal temperatures to reach a normal operat ing level It would normally take one additional hour to stabilize a unit that is 10 C 18 F outside the specified temperature range Recommended Test Equipment The test equipment listed in Table 2 1 or equivalent is suggested to make the performance checks NOTE The performance limits in this procedure do not include test equipment
82. rate this product without covers or panels installed Do not apply power to the plug in via a plug in extender SERVICE SAFETY SUMMARY FOR QUALIFIED SERVICE PERSONNEL ONLY Refer also to the preceding Operator Safety Summary Do Not Service Alone Do not perform internal service or adjustment of this product unless another person capable of rendering first aid and resuscitation is present Use Care When Servicing With Power On Dangerous voltages may exist at several points in this product To avoid personal injury do not touch exposed connections and components while power is on vi Disconnect power before removing protective panels soldering or replacing components Power Source This product is intended to operate in a power module connected to a power source DM 5120 or from a power source DM 5520 that will not apply more than 250 volts rms between the supply conductor and ground protective ground connection by way of the grounding conductor in the power cord is es sential for safe operation DM 5120 5520 Service Manual Section 1 THEORY OF OPERATION Introduction This section contains an overall functional description of the DM 5120 5520 Detailed schematics and com ponent location drawings are located at the end of this instruction manual Overall Functional Description A simplified block diagram of the DM 5120 5520 is shown in Figure 1 1 The instrument may be divided into two sections analog
83. ration mode When the calibra tion mode is on the CAL LOCK indicators will be lit in the display Calibration Mode Program 36 To calibrate the DM 5120 from the front panel you must enter the calibration mode using Program 36 NOTE Before you enter calibration mode you must enable calibration with the CAL LOCK switch CAL LOCK indicators must be lit in display To select Program 36 press the PROGRAM KEY LED ON then the numeric keys 3 and 6 If the CAL LOCK indicators are not lit in the display error code 260 will be displayed and the calibration mode will not be entered DM 5120 5520 Service Manual Front Panel Calibration Command Sequence 1 Prepare instrument for calibration as described in this section Select function and range to be calibrated Connect the appropriate calibrator for the function selected Select Program 36 The first calibration point is displayed Set the calibrator output to match the displayed calibration point Press the ENTER key The next calibration point is displayed Set the calibrator output to match the displayed calibration point Press the ENTER key Except for DCV function the entered calibration points are updated stored and the calibration program is ended for the selec ted function and range For the DCV function only a third calibration point is displayed For DCV function ranges set the DC voltage cal ibrator output
84. s have six unique digits The country of manufacture is identified as follows B000000 Tektronix Inc Beaverton Oregon USA 100000 Tektronix Guemsey Ltd Channel Islands 200000 Tektronix United Kingdom Ltd London 300000 Sony Tektonix Japan 700000 Tektronix Holland NV Heerenveen The Netherlands PREFACE This Service manual provides only servicing information intended for use by qualified service persons No operating information 15 included in this manual For instrument specifications and operating information refer to the DM 5120 5520 Instruction Manual Additional Documentation for the 5120 5520 Instruction Manual 070 7331 XX Instrument Interfacing Guide 070 7329 XX Reference Guide 070 7330 DM 5120 5520 Service Manual sassa TABLE OF CONTENTS List of Illustrations iv Front Panel Calibration Procedure 3 4 List of Tables iv Introduction 3 4 Operator s Safety Summary 1 Calibrate DC VORS 3 4 Service Safety Summary vi 2 Calibrate Resistance W 3 6 3 Calibrate Volts 3 8 DUE OPERATION 4 Check Adjust AC Volts at 70 kHz 3 8 Intr
85. stabilize f Press the ENTER key The display prompts 300 0000 mV DM 5120 5520 Service Manual Calibration j Press the ENTER key The DOV calibration points are updated stored for the selected range and the DCV function returns to normal g Set the DC voltage calibrator to 0 3000000 V Allow a few seconds for the voltage to stabilize h Press the ENTER key The display prompts 000 0000 mV k Repeat steps d through j for the remaining DCV ranges using Table 3 2 and Fig 3 1 as guide i Set the DC voltage calibrator to 0 0000000 V Allow a few seconds for the voltage to stabilize 000 0000 V Table 3 2 DC VOLTS CALIBRATION Front Panel Front Panel IEEE 488 Bus DMM DCV DMM Calibration DC Calibrator GPIB Range Set Up Point DCV Setting Commands DCV RANGE 1 300 mV Fig 3 1 300 0000 mV 0 3000000 V CAL FIRST 300E 3 300 0000 mV 0 3000000 V CAL SECOND 300E 3 000 0000 mV 0 0000000 V CAL 5 0 DCV RANGE 2 3 V Fig 3 1 A 3 000000 V 3 000000 V CAL FIRST 3 3 000000 V 3 000000 V CAL SECOND 3 0 000000 V 0 000000 V CAL LAST 0 3 30 V Fig 3 1 B 30 00000 V 30 00000 V CAL FIRST 30 30 00000 V 30 00000 V CAL SECOND 30 00 00000 V 00 00000 V CAL LAST 0 DCV RANGE 4 300 V Fig 3 1 B 300 0000 V 300 0000 V CAL FIRST 300 300 0000 V 300 0000 V CAL SECOND 300 000 0000 V CAL LAST 0 a When sending GPIB commands for dc volts calibration the dc calibrator ou
86. ta is used by the microprocessor to calculate the final reading The precharge amplifier U20B is momentarily se lected by Q31 just before signal FET Q30 is activated The purpose of the precharge amplifier is to get the signal seen by the input buffer amplifier closer to the SIGNAL 300 mVDC 3 VDC OHMS SENSE HI PRECHARGE SIGNAL DCA SIGNAL ACV ACA 2 1 V REFERENCE ZERO EXCEPT 30 V OHMS REF LO 300 OHMS 3 k OHMS OHMS REF LO 30 k OHMS OHMS SENSE LO ZERO 30 V OHMS REF LO 300 k 300 M OHMS SIGNAL 30 VDC 300 VDC OHMS REF HI Fig 1 4 JFET Multiplexer actual input at signal FET Q30 The precharge amp lifier also provides the drive to Keep the FETs on until turned off by the control circuitry 42 1 V Reference Source Diagram 6 Voltage and current measurements are based on comparing the unknown signal with an internal 2 1 V reference voltage source During each measure ment cycle the unknown signal is sampled and then compared with signal common and the 21 V reference values DM 5120 5520 Service Manual OHMS REFERENCE HI PHASE REFERENCE PHASE REFERENCE LO PHASE CALCULATE A READING CALCULATE A READING A TYPICAL VOLTAGE AND CURRENT MEASUREMENTS B TYPICAL RESISTANCE MEASUREMENTS Fig 1 5 Multiplexer Phases 034 provides a highly stable 6 95 V reference while U13 and R10 provide a constant current to minimize zener voltage variations R36 a
87. the EXTERNAL TRIGGER Input Timing for the microprocessor is accomplished by the use of Y101 an 8 MHz crystal Internally this frequency is divided down by four to obtain a bus operating frequency of 2 MHz DM 5120 5520 Service Manual Instrument operation software is stored in EPROMs U105 and U106 The revision level of this software is displayed by the ID command Calibration constants and instrument set up conditions are stored in E2PROM U20 99 is the RAM Partial address decod ing is used in this system The function selected is determined by the state of A11 A12 A13 A14 and A15 address lines These address lines determine which is selected by the decoders 01 Only device ROM RAM VIA etc will have access to the data bus at any one time The heart of the IEEE 488 circuitry is the GPIBA U5 The GPIBA is capable of performing all IEEE talker listener protocols The bidirectional data lines DO through D7 permit the transfer of data between the microprocessor and the GPIBA The transceivers U6 and U7 are used to drive the output Data is buffered by U6 and U7 and is transmitted to the bus via con nector J17 Display Circuitry Diagrams 1 amp 2 The display information is sent through display latches U11 and U12 Upon each display update new seg ment information is presented to the display latches DM 5120 5520 Service Manual Theory of Operation and a clock pulse is sent on PAO U8 The clock pulse
88. tion FRONT PANEL CALIBRATION PROCEDURE Introduction Prepare the instrument as explained in Preparation for Calibration earlier in this section This procedure calibrates the DM5120 5520 using the default calibration points in Program 36 If you change the calibration points the calibrator output values will also have to be changed accordingly If different calibration point is to be used enter the new value using the numeric keys 0 through 9 Each press of a data button displays the number at the cursor location at the bright flashing digit and moves to the next digit If the cursor is moved past the least significant digit it will move back to the most significant digit NOTE In the following procedure the DM 5120 and DM 5120 instruments will be referred to as the DMM 1 Calibrate DC Volts a Select DCV function b Select DOV range of 300 mV c Connect the DMM to the DC voltage calibrator Fig 3 14 3 4 A 300 mV and 3 V Ranges DC VOLTAGE DIVIDER OUTPUT CALIBRATOR MODEL 5440A DC VOLTAGE CALIBRATOR MODEL 5440A Fig 3 1 DC Volts Calibration Configuration NOTE Low level measurement techniques should be used when calibrating the 300 mV DC range Refer to Section 2 of the Instruction Manual for low level measurement considerations d Select Program 36 The display prompts 300 0000 mV e Set the DC voltage calibrator to 0 3000000 V Allow a few seconds for the voltage to
89. to U4 and U5 see diagram 1 shifts a digit enable bit to the next digit to be enabled Every 10 times the display is updated a digit enable is gen erated at PA1 U8 and goes to the data input of the shift register U11 and U12 are the drivers for the LED segments of the display digits and the LED indicators Power Supplies Diagram 3 The main power supplies of the DM 5120 5520 are located on this diagram Fuse F2 is the primary fuse which is mounted on the digital board 26 Vac primary power is supplied by the power module to the power transformer T1 T1 has two secondary windings one for the 5 V analog supply and one for the 215 V analog supply CR1 and CR2 provide fullwave rec tification for the two supplies while U21 U22 and U23 provide the regulation The 5 V digital supply is derived from 8 sup plied by the power module 16 Regulation is provided by U18 Fuse protection for the 5 V digi tal supply is provided by F3 located on the digital board Section 2 PERFORMANCE CHECK PROCEDURE Introduction This procedure verifies that the DM 5120 or DM 5520 is operating within the limits of the performance re quirements as listed in the Specification section of the DM 5120 5520 Instruction manual This procedure may be used to determine acceptability of mance in an incoming inspection facility it may also be used whenever there is a question of instrument accuracy following repai
90. to the third displayed calibration point 10 Press ENTER The entered DCV calibration points are updated stored and the calibration program is ended for the selected DCV range DM 5120 5520 Service Manual Calibration GPIB Calibration Command Sequence 1 Prepare instrument for calibration as described in this section NOTE See Tables 3 2 through 3 6 for calibration set tings and GPIB commands Notice that when sending GPIB calibration commands the first calibration point is positive the second is posi tive and the last is zero Send the appropriate commands to select function and range to be calibrated For example FUNCT DCV RANGE 1 selects dc volts function with range of 300 mV Connect the appropriate calibrator for the function selected Set the calibrator output for the first calibration point for DCV in 300 mV range it s 0 3000000 V Send CAL FIRST 300E 3 over the GPIB Set the calibrator output for the next calibration point for DCV in 300 mV range it s 0 3000000 Send CAL SECOND 300E 3 over the GPIB The CAL SECOND command is used only for the DCV function Set the calibrator output for the last calibration point for DCV in 300 mV range 15 0 0000000 V Send CAL LAST 0 over the GPIB The calibration points are updated stored after the CAL LAST command is sent 10 Repeat steps 2 through 9 for each function and range to be calibrated Calibra
91. tput voltage must be set to positive first negative second and zero last DM 5120 5520 Service Manual 3 5 rh r Calibration prob e Comf of 2 Calibrate Resistance o a Select function b Select range of 300 0 c Connect the DMM to the resistance calibrator as shown in Fig 3 2 A d Select Program 36 The display prompts 190 0000 0 e Set the resistance calibrator to 190 0000 0 Allow a few seconds for the resistance to stabilize f Press the ENTER key The display prompts 000 0000 Q g Set the resistance calibrator to SHORT 0 0 Allow a few seconds for the resistance to stabilize h Press the ENTER key The Q calibration points are updated stored for the selected range and the function returns to normal Ohms i Repeat steps d through h for the remaining ranges using Table 3 3 and Fig 3 2 as a guide 3 6 A Four Wire Configuration 300 Ohm to 30 k Ohm Ranges OUTPUT HI RESISTANCE CALIBRATOR MODEL 5450A B Two Wire Configuration 300 k Ohm to 300 M Ohm Ranges OUTPUT RESISTANCE x MODEL 54504 OUTPUT LO Fig 3 2 Resistance Calibration Configuration DM 5120 5520 Service Manual DMM Range 300 9 3 30 300 3 30 300 7 P oe D i 15 F Y b 4 9 y

TEK DM 5120_5520_svc_sm

Contents

Download Pdf Manuals

Related Search

Related Contents