Service Manual
Contents
1. LDS04016 Figure 4 15 Transformer Secondary Voltage Check Troubleshooting 4 19 Manual Changes Introduction This appendix contains the information required to adapt this manual to earlier versions or configurations of the 4338B than the current printing date of this manual The information in this manual applies directly to 4338B Milliohmmeter whose serial number prefix is listed on the title page of this manual Manual Changes To adapt this manual to your 4338B refer to Table A 1 and make all of the manual changes listed opposite your instrument s serial number Instruments manufactured after the printing of this manual may be different from those documented in this manual Later instrument versions will be documented in a manual changes supplement that will accompany the manual shipped with that instrument If your instrument serial number is not listed on the title page of this manual or in Table A 1 it may be documented in a yellow MANUAL CHANGES supplement For additional information on serial number coverage refer to 4338B Operation manual Table A 1 Manual Changes by Serial Number Serial Prefix Make Manual Changes or Number There are no earli2. DT HILUONMMETER ENTRY R 12 846m X 0 0001m LL TU f E ef desse AOS oa UNKNOWN O Cumprir Cont kk O memo O OBO Se UBE E HS BO BDODO 3 D I a D E gt 07 LDS03102 Reference Agilent Part Qty Description Designation Number 1 04263 04004 1 Cover 2 5041 9167 4 Foot 1460 1345 2 Tilt Stand 3 04338 65020 1 Front Panel Assembly 5041 9170 2 Trim Side 0515 0914 4 Screw M3 Hidden 5 04263 40001 1 Front Bezel2 6 04263 00605 1 Sub Panel Hidden 0515 0914 4 Screw M3 Hidden 0515 1550 2 Screw M3 Hidden 0160 4808 4 Capacitor 470 pF Hidden 1901 1250 8 Diode Hidden 7 1250 0252 4 BNC Connector 2950 0035 4 Nut 5040 3324 4 Insulator 5040 3325 4 Insulator Hidden 04263 01221 4 Lug Terminal Hidden 8 1510 0130 1 Binding Post 2190 0067 1 Washer Hidden 2950 0006 1 Nut Hidden 9 04338 87121 1 Panel Label 1 The assembly consists of the parts designated by 5 through 9 2 This part is included in the Front Panel Assembly 3 Assembly Replacement 3 5 Table 3 5 Replaceable Mechanical Parts List 2 w 5 4 L8S03003 Reference Agilent Part Qty Description Designation Number 1 04263 61615 1 GPIB Connector wi
3. Equipment Requirements Recommended Model Qty Use Multimeter DC V Accuracy lt 1 3458A 1 T Standard Resistors No Substitute 42030A 1 A Open Termination No Substitute 4209043 LIA Short Termination No Substitute 42091 A 1 A Computer No Substitute HP 9000 series 200 or 3004 1 A RAM gt 4M bytes Operating System BASIC 5 1 or higher 98616A 1 A Adjustment Program No substitute Agilent PN 04338 65005 1 A 1 Troubleshooting 2 Adjustment 3 This model is also included in the 42100A Four Terminal Pair Resistor Set 4 Excluding the 9826A Table 1 2 Required Language Extensions Name Ver Name Ver Name Ver Name Ver CLOCK 5 0 CS80 5 0 GRAPH 5 2 KBD 5 1 COMPLEX 5 1 EDIT 5 1 GRAPHX 5 2 MAT 5 1 CRTA 5 1 ERR 5 1 GPIB 5 0 MS 5 1 CRTX 5 1 FGPIB 5 0 IO 5 1 PDEV 5 0 1 This language extension depends on the mass storage type used 1 2 General Information Adjustment Introduction This chapter describes the adjustment required to ensure the 4338B is within its published specifications after it has been repaired The adjustment should be performed along with periodic maintenance to keep the 4338B in optimum operating condition If proper performance cannot be achieved after adjustment proceed to Chapter 4 Note To ensure proper results and correct instrument operation a 30 minute I warm up and stabilization is required before performing
4. Remove the five screws which secure the A5 assembly to the chassis from the side 5 Slide the A5 assembly toward the right to remove the switch on the A5 assembly from the line switch plate slot 3 10 Assembly Replacement 6 Remove the A5 assembly from the chassis Keyboard Assembly Removal Removal Procedure 1 2 o N Ba O A C Remove the cover referring to Cover Removal Disconnect the two flatcable assemblies and the wire assembly from the front side of the A2 assembly Remove the two flat head screws that secure the front panel from the bottom Remove the side trim label from both sides of the front bezel Remove four screws that secure the front panel bezel to the chassis from both sides Place the front panel assembly so that the front panel faces down Remove the screw that secures the keyboard to the front panel bezel Remove the keyboard assembly from the front panel bezel LCD Assembly Removal Removal Procedure 1 2 O o C O A C Remove the cover referring to Cover Removal Disconnect the two flatcable assemblies and the wire assembly from the front side of the A2 assembly Remove the two flat head screws that secure the front panel from the bottom Remove the side trim label from both sides of the front bezel Remove the four screws that secure the front panel bezel to the chassis from both sides Place the front panel assembly so that the front p
5. In addition it violates safety standards of design manufacture and intended use of the instrument The Agilent Technologies assumes no liability for the customer s failure to comply with these requirements Note 4338B complies with INSTALLATION CATEGORY II and POLLUTION DEGREE 2 i in IEC1010 1 4338B is INDOOR USE product w Ground The Instrument To avoid electric shock hazard the instrument chassis and cabinet must be connected to a safety earth ground by the supplied power cable with earth blade DO NOT Operate In An Explosive Atmosphere Do not operate the instrument in the presence of flammable gasses or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard Keep Away From Live Circuits Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified maintenance personnel Do not replace components with the power cable connected Under certain conditions dangerous voltages may exist even with the power cable removed To avoid injuries always disconnect power and discharge circuits before touching them DO NOT Service Or Adjust Alone Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT Substitute Parts Or Modify Instrument Because of the danger of introducing additional hazards do not install substitute parts or pe
6. that secure the Al assembly to the chassis by rotating them with a flat bladed screwdriver 5 Remove the three screws that secure the Al assembly to the chassis Remove the Al assembly from the chassis by sliding the assembly toward forward before lifting A2 CPU Board Assembly Removal Removal Procedure 1 2 Remove the cover referring to Cover Removal Disconnect the two flatcable assemblies and the wire assembly from the front side of the A2 assembly Disconnect the flatcable assembly which is connected to the GPIB connector on the rear panel from the rear right side of the A2 assembly Remove the four screws that secure the A2 assembly to the stud 5 Remove the flat cable assembly which is connected to the Al main board assembly on the bottom while sliding the A2 assembly toward front 6 Remove the A2 assembly from the chassis Note The ROM and EEPROM on the A2 assembly may be transferred to the new I assembly to minimize the repair time and parts cost Refer to Replacing the w A2 CPU Board Assembly for more information A5 AC Inlet Board Assembly Removal Removal Procedure 1 2 3 Disconnect the cable assembly with the 4 pin connector from the A5 assembly Disconnect the cable assembly with the 3 pin connector from the A5 assembly Remove the screw which fixes the green and yellow wire connected to the neutral terminal of the power cable connector to the chassis bottom
7. 0515 0914 2 Screw M3 Flat Head 10 04263 01201 1 Plate Line Switch 11 0515 0914 5 Screw M3 Flat Head for A5 Assembly Replacement 3 7 Table 3 7 Replaceable Mechanical Parts List 4 PO UP B V o Yellow Gray White e I Gray Orange Gray White selector l OO O oq lag D gt ST ALE Ah cem 4 Reference Agilent Part Qty Description Designation Number 1 04263 61608 1 Wire Assy V Selector 2 04263 61602 1 Cable Assembly A A 04339 25004 1 Core Holder 0515 1550 1 Screw M3 3 04263 61604 1 Cable Assembly B B 04339 25004 1 Core Holder 0515 1550 1 Screw M3 4 04263 61605 1 Cable Assembly C C 04339 25004 1 Core Holder 0515 1550 1 Screw M3 5 04338 61603 1 Cable Assembly 6 04339 61614 1 Wire Assy Binding Post 3 8 Assembly Replacement Disassembly Procedures This section provides the procedures to disassemble the 4338B s major assemblies Tools and fasteners requir
8. 2 1 2 Required Language Extensions 1 2 2 1 Related Adjustment 2 2 3 1 Replaceable Major Assembly List 3 3 3 2 A2 CPU Board Assembly Replaceable Assembly List 3 4 3 3 Replaceable Assembly List LG 3 4 3 4 Replaceable Mechanical Parts List AA 3 5 3 5 Replaceable Mechanical Parts Lit2 3 6 3 6 Replaceable Mechanical Parts Lit4t3 2 008 3 7 3 7 Replaceable Mechanical Parts Lit4 2 2 00 3 8 4 1 DC DC Converter Output Voltage Connected 4 13 4 2 DC DC Converter Open Output Voltages UA 4 18 A 1 Manual Changes by Serial Number a A 1 Contents 3 General Information Introduction This chapter provides information on instruments covered by this manual and required equipment for the adjustment and troubleshooting Instruments Covered by This Manual Agilent Technologies uses a two section nine character serial number which is printed on the serial number label Figure 1 1 attached to the instrument s rear panel The first five characters are the serial prefix and the last five digits are the suffix Agilent Technologies Japan Ltd SERNO JP1KG12345 AK MADE IN JAPAN 33 Figure 1 1 Serial Number Label An instrument manufactured after the printing date of this manual may have a serial n
9. a magnitude and a phase The DUT resistance is the real part of vector impedance which is determined by the vector ratio between the voltage across the DUT and the current flowing through the DUT L8504001 Figure 4 1 Voltage Current Ratio Measurement Principle In Figure 4 1 a DUT is connected in series with a signal source voltmeter V and ammeter A If the ammeter measures i amperes when the source voltage is v volts the DUT s impedance Zx is expressed by Zz 2 The DUT resistance R is the real part of Zx expressed in the complex real imaginary number format Ze R jX where j is the imaginary unit and X is the reactance Note For accurate and stable low resistance measurement the 4338B employs an ac I voltage source rather than a dc voltage source w The 4338B essentially consists of a signal source a vector voltmeter and a vector current meter Troubleshooting 4 3 Overall Block Diagram Figure 4 2 shows the overall block diagram of the 4338B Current Sense Source Resistor T Voltage Sense Amplifier L8504002 Figure 4 2 4338B Overall Block Diagram The signal source section applies measurement signal to the range resistor and DUT in series The current sense amplifier measures the voltage across the range resistor which is proportional to the current flowing through the DUT The voltage sense amplifier
10. replaceable parts lists and the step by step disassembly procedures for the major assemblies Table 3 1 to Table 3 7 describe all the 4338B replaceable parts The figure section of Table 3 7 also shows the cable connections Ordering Information To order a part listed in the replaceable parts lists quote the Agilent Technologies part number indicate the quantity required and address the order to the nearest Agilent Technologies office To order a part that is not listed in the replaceable parts list include the instrument model number complete instrument serial number the description and function of the part and the quantity of parts required Address the order to the nearest Agilent Technologies office Restored Exchange Assemblies Some replacement assemblies are available as either new or restored assemblies The restored assembly is more economical than a new assembly and as with new assemblies a 90 day warranty applies through the instrument s support life The defective assembly must be returned for credit For this reason new assemblies must be ordered for spare parts The part numbers for both new and restored assemblies are given in the replaceable parts lists Note The Exchange Program may not apply in your country Contact the nearest I Agilent Technologies office for further details k Assembly Replacement 3 1 Replacing the A2 CPU Board Assembly The A2 CPU Board Assembly has a ROM for the firmware
11. the adjustment k Safety Consideration This chapter contains NOTES CAUTIONS and WARNINGS which must be followed to ensure operator safety and to maintain the instrument in a safe and serviceable condition The adjustment covered in this chapter should be performed only by a qualified person who is aware of the hazards Warning Any interruption of the protective ground conductor inside or outside the instrument or disconnection of the protective ground terminal can make the instrument dangerous Intentional interruption of the protective ground system for any reason is prohibited Required Equipment Table 1 1 lists the equipment required to perform the adjustment Use only calibrated standards when adjusting the 4338B Adjustment 2 1 Adjustment Tools No hand tools are required for the adjustment Adjustable Components There are no adjustable components such as variable capacitors or variable resistors in the 4338B Adjustment is performed by updating the adjustment data stored in the EEPROM Factory Selected Components No factory selected components are used in the 4338B EEPROM Write Protect Switch There are no EEPROM write protect switches in the 4338B Related Adjustment There is only one adjustment for the 4338B Table 2 1 lists the adjustment that must be performed if an assembly has been replaced Table 2 1 Related Adjustment Assembly Replaced Required Adjustment
12. the adjustment being performed follows right after EEPROM replacement change switch A2SW1 1 to CLOSE so that the 4338B will ignore the self test I w errors at power on Return the switch to OPEN when the adjustment has been completed Refer to Figure B 1 for the switch location 2 4 Adjustment Adjustment Procedure References This section provides supplemental information for the adjustment which is performed by the program Connection instructions and some additional explanations are provided Use this chapter as a reference when performing the adjustment Resistance Measurement Adjustment This adjustment updates the data to adjust the measurement resistance to the standard values Equipment Standard Resistors 42030A Open Termination 42090A Short Termination 42091A Setup This setup obtains the range resistor adjustment data and the process amplifier attenuator adjustment data Computer O e0000 42090A 42091A 42020A OPEN SHORT Standard x Direct connection Termination Termination Resistors no cable LDS02002 Figure 2 2 Range Resistor Adjustment Setup Perform the following steps as the program instructs 1 Connect the specified termination or standard resistor directly to the 4338B UNKNOWN Connectors 2 Repeat step 1 as instructed Adjustment 2 5 Assembly Replacement Introduction This chapter provides the 4338B
13. 1 1 DC DC Converter Unit 4 04263 66532 1 A2 CPU Board Assembly w o ROM 04263 00604 1 Case Shield 0515 1550 4 Screw M3 5 04338 66504 1 A4 Keyboard Assembly 04338 25151 1 Rubber Key 0515 1550 1 Screw M3 6 04263 61010 1 LCD Assembly 04263 25003 1 Filter Transparent 0515 1550 2 Screw M3 7 04338 66551 1 Al Main Board Assembly 1 Included in 04263 66532 Assembly Replacement 3 3 Table 3 2 A2 CPU Board Assembly Replaceable Assembly List DO A 0000 Good Reference Agilent Part Qty Description Designation Number 1 2110 1123 1 A2F1 Fuse SMT 2A 2 1818 5146 1 A2U1 EEPROM 3 04338 85031 1 A2U11 ROM Rev 1 00 Table 3 3 Replaceable Assembly List Reference Agilent Part Qty Description Designation Number A1C500 0180 4334 1 Capacitor 22000 F for power supply A1C501 0180 4334 1 Capacitor 22000 F for power supply A5SW1 3101 3171 1 Line Switch A5VR1 0887 0237 1 Varistor A5VR2 0887 0237 1 Varistor 3 4 Assembly Replacement Replaceable Mechanical Parts List The replaceable mechanical parts are listed in Table 3 4 to Table 3 7 Table 3 4 Replaceable Mechanical Parts List 1
14. A1 Main Board Assy Resistance Measurement Adjustment A2 CPU Board Assy without ROM None Ab AC Inlet Board Assy None LCD Assembly None DC DC Converter Unit None Keyboard Assembly None 1 If the EEPROM A2U1 is replaced the Resistance Measurement Adjustment is required 2 2 Adjustment Adjustment Program The adjustment program listed in Table 1 1 is required for the adjustment Using the program the computer controls the 4338B to obtain the adjustment data and stores the data in the 4338B internal EEPROM A2U1 The adjustment program runs on the computer listed in Table 1 1 The program should be installed into your computer according to the procedure described in Program Installation To start the program after it has been installed refer to Program Execution Figure 2 1 shows the adjustment program flow The following lists the brief explanation for each menu item Main Menu Resistance Rewrite Measurement UP Adjustment PROM Y Y Y in Menu Main Menu Main Menu L8502001 Figure 2 1 Adjustment Program Flow INITIAL SETUP defines the standards calibration values Update the standard s calibration values if necessary Resistance obtains the data to adjust the actual measurement resistance to the Measurement standards value and writes the data both to the 4338B internal EEPROM Adjustment and to the unit se
15. Agilent 4338B Milliohmmeter Service Manual SERIAL NUMBERS This manual applies directly to instruments with serial number prefix JPIKD For additional important information about serial numbers read Instruments Covered by This Manual in Chapter 1 of this manual m E Agilent Technologies Toe te one Agilent Part No 04338 90033 Printed in JAPAN March 2001 Notice The information contained in this document is subject to change without notice This document contains proprietary information that is protected by copyright All rights are reserved No part of this document may be photocopied reproduced or translated to another language without the prior written consent of the Agilent Technologies Agilent Technologies Japan Ltd Component Test PGU Kobe 1 3 2 Murotani Nishi ku Kobe shi Hyogo 651 2241 Japan Copyright Agilent Technologies Japan Ltd 1996 2000 2001 Manual Printing History August 1996 First Edition part number 04338 90083 June 2000 aaaea arrear Second Edition part number 04338 90083 March 2001 e ee Third Edition part number 04338 90033 Safety Summary The following general safety precautions must be observed during all phases of operation service and repair of this instrument Failure to comply with these precautions or with specific WARNINGS elsewhere in this manual may impair the protection provided by the equipment
16. ad of A2F1 Fuse Check 9 Fuse and Line Switch 1 Check that the fuse on the 4338B rear panel is not blown 2 Check that the line switch on the A5 AC Inlet Board Assembly is not defective 3 If passed proceed to Check 10 DC DC Converter Input Voltage otherwise replace the defective line switch or blown fuse 416 Troubleshooting Check 10 DC DC Converter Input Voltage 1 Turn on the 4338B 2 Using a multimeter check if the voltage between DC OUT test pad and TP500 DC DC Converter input voltage is between 12 V and 15 Vdc Refer to Figure 4 13 for test pad and pin locations 3 If the voltage is in range proceed to the Check 11 DC DC Converter Open Output Voltages otherwise proceed to the Check 12 Transformer Secondary Voltage DC OUT LDS04012 Figure 4 13 Test Pin Locations Troubleshooting 4 17 Check 11 DC DC Converter Open Output Voltages 1 Turn off the 4338B 2 Disconnect the DC DC Converter Output Cable shown in Figure 4 14 from connector J504 o
17. afety checks to verify the safety condition of the 4338B these checks may also be used for safety checks after troubleshooting and repair 1 Visually inspect the interior of the instrument for any signs of abnormal internally generated heat such as discolored printed circuit boards and components damaged insulation or evidence of arcing Determine the cause and repair Use an ohmmeter which can accurately measure 0 1 Q to check the resistance from the instrument enclosure to the power cord s ground pin The resistance must be less than 0 1 Q Flex the power cord while making this measurement to determine if any intermittent discontinuities exist Unplug the 4338B s power plug from the power source Set the line switch to ON Tie the line and neutral pins of the power connector together and check the resistance between them and enclosure The minimum acceptable resistance is 5 MQ Find and replace any component which causes the instrument to fail this test Verify that the correct fuse is installed 5 Verify that the grounding wire green and yellow is secured to the chassis by a screw and washer 4 2 Troubleshooting Theory of Operation This section describes the general overall operation of the 4338B and the operation of each assembly Overall Measurement Theory The 4338B measures the resistance of the Device Under Test DUT by measuring vector voltage to current ratio A vector is a value which consists of
18. and an EEPROM for the adjustment data and user data Both ROM and EEPROM are mounted in sockets for easy replacement If the A2 assembly is replaced the ROM and EEPROM may be transferred from the defective assembly to the new assembly as long as the ROM and EEPROM are not defective The ROM transfer reduces parts cost for the repair and the EEPROM transfer saves time from readjusting the 4338B For this purpose the A2 assembly can only be ordered without the ROM When the A2 assembly is replaced make sure that the jumpers and switches on the A2 assembly are in the default position as shown in Appendix B Replaceable Assembly List The replaceable electrical assemblies are listed in Table 3 1 and Table 3 3 3 2 Assembly Replacement Table 3 1 Replaceable Major Assembly List LDS0301 D a Tab A LD e _A2J4 Dl O BP To AZJ4 To A2J5 To A2J3 Reference Agilent Part Qty Description Designation Number 1 04263 66505 1 A5 AC Inlet Board Assembly 2 04263 60004 1 Transformer Assembly 3 04263 8090
19. anel faces down Remove the two screws that secure the LCD to the front panel bezel Remove the LCD assembly from the front panel bezel BNC Connector Removal Removal Procedure 1 DO Jo Q a C Remove the cover referring to Cover Removal Disconnect the two flatcable assemblies and the wire assembly from the front side of the A2 assembly Remove the two flat head screws that secure the front panel from the bottom Remove the side trim label from both sides of the front bezel Remove four screws that secure the front panel bezel to the chassis from both sides Place the front panel assembly so that the panel faces down Disconnect the cable assembly which is connected to the BNC being replaced connector from the Al main board assembly Assembly Replacement 3 11 8 Remove the core holder which holds the cable assembly which is connected to the BNC connector being replaced by unscrewing the screw secures the holder from the front side 9 Disconnect the cable from the BNC connector housing being replaced by unscrewing the nut which fastens from the back of the front panel the cable to the BNC connector 10 Unscrew the nut which connects the BNC connector housing to the sub panel 11 Remove the BNC connector 3 12 Assembly Replacement Troubleshooting Introduction This chapter provides assembly level troubleshooting information for the 4338B The information includes theory of o
20. ccc Manual Changes A Default Jumper and Switch Settings Introduction Jumper and Switch Settings Xu Index Contents 2 Figures 1 1 Serial Number Label a a a a a a l 1 2 1 Adjustment Program Flow A 2 3 2 2 Range Resistor Adjustment Setup AU 2 5 3 1 Cover Removal aoaaa c r s c e s s s o o e 3 9 4 1 Voltage Current Ratio Measurement Principe 4 3 4 2 4338B Overall Block Diagram c Xo 4 4 4 3 Analog Section Block Diagram 4 5 4 4 Signal Source Section Block Diagram 4 6 4 5 Range Resistor and Current Sense Amp Block Diagram 2 2 4 7 4 6 Voltage Sense Amp and Process Amp Block Diagram 4 8 4 7 Digital Section Block Diagram 2 2 4 9 4 8 Power Supply Section Block Diagram 4 10 4 9 Troubleshooting Flow 2 ce ee 4 12 4 10 DC DC Converter Output VoltageChek GA 4 13 4 11 CPU Board Assembly LED Light Sequence 2 ae 4 15 4 12 Location of High Lead of A2Fl Fuse 4 16 4 13 Test Pin Locations 4 17 4 14 DC DC Converter Output Connector 2 4 18 4 15 Transformer Secondary Voltage Check 2248 4 19 B 1 Jumper and Switch Settings B 1 Tables 1 1 Required Equipment 1
21. d TP500 shown in Table 4 1 on Al Main Board Assembly are in the ranges shown 4 If passed proceed to Check 2 LCD Displays Anything otherwise proceed to Check 9 Fuse and Line Switch 12 V LDS04008 Figure 4 10 DC DC Converter Output Voltage Check Table 4 1 DC DC Converter Output Voltage Connected Test Pad Test Pin Range 5 V 500 5 1 0 2 V 12 V 500 1240 6 V 12V 500 12 0 6 V Troubleshooting 4 13 Check 2 LCD Displays Anything 1 Turn off the 4338B 2 Turn on the 4338B while watching the LCD 3 Check for a beep sound for a moment and if you see anything is displayed on the LCD 4 If beep sounds and LCD displays something proceed to Check 3 LCD Operates Correctly otherwise proceed to Check 6 CPU Power LED Lights Check 3 LCD Operates Correctly 1 Turn on the 4338B 2 Reset the 4338B 3 Check if the LCD s back light is lit 4 Press some front panel keys such as Meas Prmtr an
22. d check if the characters are correctly displayed in the whole area of the LCD 5 If the LCD operates correctly proceed to Check 4 Any Error Message on LCD otherwise replace the LCD Assembly Check 4 Any Error Message on LCD 1 Turn off the 4338B 2 Turn on the 4338B while watching the LCD 3 Check if the LCD displays any error message 4 If an error has NOT occurred replace the Al Main Board Assembly otherwise proceed to Check 5 CPU Related Error Message Check 5 CPU Related Error Message 1 If the error message is one of the following replace the A2 CPU Board Assembly otherwise replace the Al Main Board Assembly a ROM TEST FAILED b RAM TEST FAILED c EEPROM R W FAILED Note When replacing the A2 CPU Board Assembly refer to Replacing the A2 CPU I Board Assembly in Chapter 3 for handling the ROM and EEPROM on the A2 w Assembly Check 6 CPU Power LED Lights 1 Turn on the 4338B 2 Check if the LED 5 V of DSI on the A2 CPU Board Assembly lights Refer to Figure 4 11 for DS1 location 3 If the LED lights proceed to Check 7 Any Error Code on LED otherwise proceed to Check 8 CPU Fuse High Lead Voltage 414 Troubleshooting Check 7 Any Error Code on LED 1 Turn off the 4338B 2 Turn on the 4338B while watching LEDs on the A2 CPU Board Assembly 3 Check if the LEDs light in the sequence shown in Figure 4 11 4 Tf LEDs light as the sequence replac
23. e the LCD Assembly otherwise possibly HALT doesn t turn off or BERR lights replace the A2 CPU Board Assembly Note When replacing the A2 CPU Board Assembly refer to Replacing the A2 CPU I Board Assembly in Chapter 3 for handling the ROM and EEPROM on the A2 w Assembly A2 CPU Board Assy Power On U LCS04009 Figure 4 11 CPU Board Assembly LED Light Sequence Troubleshooting 4 15 Check 8 CPU Fuse High Lead Voltage 1 Turn on the 4338B 2 Using a multimeter check if the dc voltage at the high lead of the fuse F1 on the CPU Board shown in Figure 4 12 is 50 2 V 3 If the voltage is in the range replace the A2 CPU Board Assembly otherwise replace the Al Main Board Assembly Note If the multimeter reading is correct fuse Fl on the A2 CPU Board Assembly is I most suspicious Replacing only the fuse may fix the problem w Note When replacing the A2 CPU Board Assembly refer to Replacing the A2 CPU I Board Assembly in Chapter 3 for handling the ROM and EEPROM on the A2 w Assembly A2 CPU Board Assy LES04010 Figure 4 12 Location of High Le
24. ed for the replacement are described Caution SUSCEPTIBLE TO DAMAGE FROM ESD Perform the following procedures only at a static safety workstation and wear a grounding strap Tools and Fasteners The 4338B mechanical components are secured using metric threaded fasteners Many fasteners in the 4338B may appear to be Phillips type but they are in fact Pozidrive type To avoid damaging them use only pozidrive screwdrivers to remove or tighten pozidrive type fasteners Cover Removal The following procedure is common for gaining access to any of the assemblies Figure 3 1 Cover Removal 1 Remove the two screws which fasten the cover to the chassis rear panel 2 Slide the cover toward the rear while holding the front panel bezel Assembly Replacement 3 9 A1 Main Board Removal Removal Procedure 1 2 Remove the A2 CPU Board Assembly referring to A2 CPU Board Assembly Removal Disconnect the following cable assemblies and wire assemblies from the Al assembly a The three cable assemblies marked A B and C which are connected to the UNKNOWN connectors on the Front Panel b The wire assembly which is connected to the transformer c The two wire assemblies which are connected to the DC DC Converter 3 Remove the nut which fasten the Ext Trigger connector to the rear panel 4 Remove the four studs
25. er configurations than the printing date of this manual Manual Changes A 1 Default Jumper and Switch Settings Introduction This appendix describes the setting of the jumpers and switches on the A2 CPU Board Assembly Use this information when the A2 Assembly is replaced Jumper and Switch Settings Figure B 1 shows the default Jumper and Switch settings When the A2 CPU Board Assembly is replaced set the jumpers and switches to the default sides as shown in the figure A2 CPU Board Assembly Da SW1 1 If closed the power on self test errors will be ignored 0000 ooo LCS0B001 Figure B 1 Jumper and Switch Settings Default Jumper and Switch Settings B 1 Index A A1 Main Board Removal 3 10 A2 CPU Board Assembly Removal 3 10 A5 AC Inlet Board Assembly Removal 3 10 Adjustable Components 2 2 Adjustment 2 1 Adjustment Procedure References 2 5 Adjustment Program 2 3 Adjustment Tools 2 2 After Service Product Safety Checks 4 2 Analog Section 4 5 Assembly Replacement 3 1 B BNC Connector Removal 3 11 C Check Procedure References 4 13 Cover Removal 3 9 D Digital Section 4 9 Disassembly Procedures 3 9 Documentation Map vi
26. ii E EEPROM Write Protect Switch 2 2 F Factory Selected Components 2 2 G General Information 1 1 H How To Use This Manual viii I Instruments Covered by This Manual 1 1 K Keyboard Assembly Removal 3 11 L LCD Assembly Removal 3 11 M Manual Changes A 1 O Ordering Information 3 1 Overall Block Diagram 4 4 Overall Measurement Theory 4 3 P Power Supply Section 4 10 Program Installation 2 4 R Range Resistor Adjustment 2 5 Range Resistor and Current Sense Amplifier Sections 4 7 Related Adjustment 2 2 Replaceable Assembly List 3 2 Replaceable Mechanical Parts List 3 5 Replacing A2 CPU Board Assembly 3 2 Required Equipment 1 2 Restored Exchange Assemblies 3 1 S Signal Source Section 4 6 T Theory of Operation 4 3 Tools and Fasteners 3 9 Troubleshooting 4 11 Vv Voltage Sense Amplifier and Process Amplifier Sections 4 8 Index 1
27. information Troubleshooting 4 9 Power Supply Section Figure 4 8 shows the power supply section block diagram A5 AC Inlet Bd Assy Trans i REDE onverter v vRI SA IE 5 V V Select o La ili c 12V vR2 SA NEUTRAL GROUND gt HS TT 7 L8504004 Figure 4 8 Power Supply Section Block Diagram The ac line power is connected to the A5 AC Inlet Board Assembly which consists of the fuse line switch and varistors The voltage selection switch on the rear panel selects the ac line voltage from 230V or 115V According to the selection the ac line power is connected to the corresponding primary tap of the transformer Varistor VRI protects the circuit from surge voltage on the line power VR2 blows fuse FI if the 4338B is turned on with the wrong line voltage setting selection for example 115V selection when using a 230V line The transformer secondary voltage is approximately 14 V The ac voltage is rectified and filtered by circuitry on the Al Main Board Assembly and produces approximately 14V dc The dc voltage is applied to the DC DC Converter to produce regulated 4 12V 5V and 12V de The dc voltages are supplied to all assemblies either directly or indirectly via the Al assembly 410 Troubleshooting Troubleshooting Figure 4 9 shows the overall troubleshooting flowchart to fi
28. measures the voltage across the DUT The process amplifier switches these two voltages to be converted into digital data The CPU calculates DUT resistance derived from impedance from the vector ratio of these two voltages and displays the result on the LCD 44 Troubleshooting Analog Section Figure 4 3 shows the analog section block diagram The 4338B analog section can be divided in six sections the signal source range resistor current sense amplifier voltage sense amplifier process amplifier and dry circuit loop The signal source generates a 1 kHz signal of which level is set from the keyboard or by GPIB commands The signal is applied to the range resistor and to the DUT via the High Current Hcur connector The current flowing through the DUT flows into the ground via the Low Current Lcur connector and outer shield of the Hcur connector The vector current flowing through the DUT is measured by the current sense amplifier in terms of the vector voltage across the range resistor The vector voltage across the DUT is measured by the voltage sense amplifier The process amplifier selects one of the above two vector voltages The selected voltage is processed according to measurement conditions such as signal source level and measurement range and is converted into digital data by the Analog to Digital Converter ADC The dry circuit loop attains the dry circuit mode by limiting the signal source output so that the voltage ac
29. n the Al Main Board Assembly 3 Turn the 4338B on 4 Using the multimeter check if the DC DC Converter open output voltages on the output connector pins shown in Figure 4 14 are in the ranges shown in Table 4 2 5 If passed replace the Al Main Board Assembly otherwise replace the DC DC Converter Assembly LDS040H Figure 4 14 DC DC Converter Output Connector Table 4 2 DC DC Converter Open Output Voltages Pin Pin Voltage Range 1 2 5 1 0 1 V 4 3 12 0 6 V 5 3 12 0 6 V 4 18 Troubleshooting Check 12 Transformer Secondary Voltage 1 Turn off the 4338B 2 Disconnect the transformer secondary connector from connector J501 on the Al Main Board Assembly Refer to Figure 4 15 for the connector location 3 Turn the 4338B on 4 Using a multimeter check if the transformer secondary voltage is between 13 V and 17Vac 5 If passed replace the Al Main Board otherwise replace the transformer
30. nd the defect assembly Follow the flowchart when troubleshooting Refer to the Check Procedure References for the detailed procedure to check each item Refer to Chapter 3 for assembly replacement Note Because of each assembly s high SMD surface mount device ratio the repair I should be done by assembly replacement The troubleshooting procedure w therefore only isolates the defective assembly Troubleshooting 4 11 ule peor del aq uren bv 9 Ajquessy A peel ysy uleW LV esn ndo 1am iv 8 42849 A Asepuodas ind no uedo JOW JOJSUBI AUOD 90 20 ON nao zv Ndo cr UIEN LY es cobessou 10418 p ej l Add S YISYD Z 30949 LL 9849 q31 uo epoo JoJe Auy uo ebessew SO 10419 Auy A yndul lt aeyeauoo 20 24 seed Soh Z A934 V 98YO 41 4S YBI OL Y90849 da Jemod ON ndo 9 499540 9949 6ulyjAue sAejdsip 91 C jJ994109 sejeJedo qo LUDLS eul pue sn4 A 1ndino led AU 90 00 ssed amp HISYD 4984 1UVIS Figure 4 9 Troubleshooting Flow 412 Troubleshooting LDS04007 Check Procedure References Refer to the corresponding check procedure Each check procedure is numbered the same as in Figure 4 9 for quick reference Check 1 DC DC Converter Output Voltage 1 Remove the cover referring to Cover Removal in Chapter 3 2 Turn on the 4338B 3 Using a multimeter check to see if the voltages between the test pads and the groun
31. ny other legal theory Assistance Product maintenance agreements and other customer assistance agreements are available for Agilent Technologies products For any assistance contact your nearest Agilent Technologies Sales and Service Office Addresses are provided at the back of this manual vi Safety Symbols General definitions of safety symbols used on equipment or in manuals are listed below 2 gt J Warning Caution Note I Instruction manual symbol the product is marked with this symbol when it is necessary for the user to refer to the instruction manual Alternating current Direct current On Supply Off Supply Frame or chassis terminal This Warning sign denotes a hazard It calls attention to a procedure practice condition or the like which if not correctly performed or adhered to could result in injury or death to personnel This Caution sign denotes a hazard It calls attention to a procedure practice condition or the like which if not correctly performed or adhered to could result in damage to or destruction of part or all of the product Note denotes important information It calls attention to a procedure practice condition or the like which is essential to highlight vii Documentation Map Operation Manual Operation Manual Agilent Part Number 04338 90030 for English edition 04338 97030 for Japanese edition explains specifications basic measuremen
32. on Figure 4 7 shows the Digital Section block diagram Board Assy dOSSsa00ud Keyboard Assy Handler L8S04006 Figure 4 7 Digital Section Block Diagram The digital section consists of the A2 CPU Board Assembly and other peripheral assemblies such as the keyboard and LCD The section communicates with the Al Main Board Assembly in order to control the latches switches and other components on the Al assembly and receive the measurement data The GPIB interface on the A2 Assembly allows the 4338B communicate with a controller A handler interface on the Al Assembly allows the 4338B communicate with an external handler The A2 CPU Board Assembly includes a processor ROM EEPROM jumpers switches and LEDs ROM A2U11 stores the firmware which controls all the 4338B s operation and functions The ROM is mounted in a socket for easy replacement The EEPROM A2U1 stores the unit unique data such as the adjustment data and the operator unique data such as the operator saved measurement setup condition The EEPROM will not lose its data when power is turned off The EEPROM is mounted in a socket for easy replacement Jumpers and switches set the 4338B s conditions Refer to Appendix B for more
33. peration and troubleshooting Safety Considerations This chapter contains WARNINGs and CAUTIONS that must be followed for your protection and to avoid damaging the equipment Warning The servicing procedures described herein are performed when power is supplied to the instrument and its protective covers are removed This type of servicing must be performed only by service trained personnel who are aware of the hazards involved for example fire and electrical shock When serving can be performed without power applied to the instrument remove power from the instrument Before any repair is completed ensure that all safety features are intact and functioning and that all necessary parts are properly connected to the protective grounding system Required Equipment Table 1 1 lists the equipment required for troubleshooting Troubleshooting 4 1 After Service Product Safety Checks Warning Whenever it appears likely that protective safety provisions have been impaired the apparatus shall be marked as inoperative and should be secured against any unintended operation The protection provisions will have likely been compromised if for example m The instrument shows visible signs of damage m The instrument fails to perform the intended measurement m The unit has undergone prolonged storage under unfavorable conditions m The instrument was severely stressed in transport Perform the following five s
34. resistor consists of four resistors which are switched according to the signal source output level The current sense amplifier which is a differential amplifier amplifies the voltage across the range resistor Troubleshooting 4 7 Voltage Sense Amplifier and Process Amplifier Sections These sections measure the voltage across the DUT and processes the outputs from the voltage sense amplifier and the current sense amplifier Figure 4 6 shows this section s block diagram from Current Sense Amplifier Voltage Sense Am Process Amplifier to Signal Source Section L8S04014 Figure 4 6 Voltage Sense Amp and Process Amp Block Diagram The voltage sense amplifier which is a differential amplifier measures the vector voltage across the DUT via the High Potential Hpor and Low Potential Lpor connectors The output of the voltage sense amplifier is fed back to the signal source section for dry circuit measurement SW1 in the process amplifier selects the inputs from the voltage sense amplifier and current sense amplifier to be processed The selected signal is attenuated according to the range resistor setting The filter passes the fundamental signal 1 kHz in order to purify the signal for accurate and stable measurement The filtered signal is converted into digital data to be processed by the digital section 4 8 Troubleshooting Digital Secti
35. rform unauthorized modifications to the instrument Return the instrument to a Agilent Technologies Sales and Service Office for service and repair to ensure that safety features are maintained Dangerous Procedure Warnings Warnings such as the example below precede potentially dangerous procedures throughout this manual Instructions contained in the warnings must be followed Warning Dangerous voltages capable of causing death are present in this instrument Use extreme caution when handling testing and adjusting this instrument Certification Agilent Technologies certifies that this product met its published specifications at the time of shipment from the factory Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology to the extent allowed by the Institution s calibration facility or to the calibration facilities of other International Standards Organization members Warranty This Agilent Technologies instrument product is warranted against defects in material and workmanship for a period of one year from the date of shipment except that in the case of certain components listed in General Information of this manual the warranty shall be for the specified period During the warranty period Agilent Technologies Company will at its option either repair or replace products that prove to be defective For warran
36. rial number dependent file on the disk This adjustment should be performed if the Impedance Measurement Accuracy performance test fails Rewrite EEPROM writes the adjustment data which is stored in the unit serial number dependent file to the EEPROM Note Make sure that the correct line frequency 50 or 60Hz has been selected in the I UUT 4338B window preceding the Main Menu This selection will improve w the adjustment data accuracy Adjustment 2 3 Program Installation The adjustment program must be installed in the computer using the following procedures Making a Working Copy Copy the content of the adjustment program disk to a working disk or to the harddisk to prevent the program file from accidental deletion or destruction Use the working disk or harddisk and store the original disk in a safe place Program Execution Perform the following steps to start the adjustment program Note Install the program prior to execution Refer to Program Installation k 1 Turn on the computer and bring up the BASIC system Refer to the Table 1 2 for the required language extensions 2 Set the Mass Storage Unit Specifier to the drive directory where the adjustment program exists using the MSI command 3 Load the program ADJ4338B by pressing LOAD ADJ4338B Return or Enter 4 Execute the program by pressing RUN Note In the program the 4338B is referred as UUT y Note If
37. ross the DUT is not more than 20 mV Current Sense Amplifie 2 cignal Source _ tage Process Amplifier _ Resistor Dry Circuit Loop L8504005 Figure 4 3 Analog Section Block Diagram Troubleshooting 4 5 Signal Source Section The signal source generates a 1 kHz signal of which output current is selected from among 1 pA 10 pA 100 A 1 mA and 10 mA in rms The output current is determined by the attenuator and the following amplifier The dry circuit loop controls the attenuation so that the voltage across the DUT is not more than 20 mV Attenuator D gt to Range Resisitor 110 0 770 0 1100 0 e Of e o V from Voltage Sense Amplifier Output Dry Circuit Loop L8S04013 Figure 4 4 Signal Source Section Block Diagram 4 6 Troubleshooting Range Resistor and Current Sense Amplifier Sections These sections measure current flowing through the DUT Figure 4 5 shows this section s block diagram __ Current Sense Amplifier from Signal Source Section Range Resistor L8504003 Figure 4 5 Range Resistor and Current Sense Amp Block Diagram The range resistor converts the current to a proportional voltage which is measured The range
38. s a 3 10 Removal Procedure AA 3 10 A2 CPU Board Assembly Removal GU 3 10 Removal Procedure AA 3 10 A5 AC Inlet Board Assembly Removal AA 3 10 Removal Procedure AA 3 10 Keyboard Assembly Removal GU 3 11 Removal Procedure CU 3 11 LCD Assembly Removal a c s cs os it os bt ts os t t 3 11 Removal Procedure CU 3 11 BNC Connector Removal 2 Xu 3 11 Removal Procedure CU 3 11 Contents 1 4 Troubleshooting Introduction 2 2 1 A Safety Considerations c c Required Equipment c After Service Product Safety Checks AA Theory of Operation Overall Measurement Theory Overall Block Diagram 2 2 a Analog Section 0 Signal Source Section GU Range Resistor and Current Sense Amplifier Sections Voltage Sense Amplifier and Process Amplifier Sections Digital Section 0 Power Supply Section UA Troubleshooting 0C AA Check Procedure References CC OX Check 7 Any Error Code on LED CC Check 8 CPU Fuse High Lead Voltage Check 9 Fuse and Line Switch 2 Check 10 DC DC Converter Input Voltage Check 11 DC DC Converter Open Output Voltages Check 12 Transformer Secondary Voltage Manual Changes Introduction
39. t explanations and how to verify conformance to published specifications Service Manual Service Manual Agilent Part Number 04338 90043 explains how to adjust troubleshoot and repair the 4338B How To Use This Manual This is the Service Manual for the 4338B Milliohmmeter This manual contains adjustments and repair information and consists of the following four chapters Chapter 1 General Information Chapter 1 gives general information for servicing the 4338B This chapter lists the recommended equipment for adjustments and troubleshooting Chapter 2 Adjustments Chapter 2 describes the adjustments required to ensure that the 4338B is within its published specifications after it has been repaired or it fails the performance tests Chapter 3 Assembly Replacement Chapter 3 provides the information on replacing the 4338B assemblies The information includes replaceable assembly lists and removal and installation procedures Chapter 4 Troubleshooting Chapter 4 provides the information on troubleshooting the 4338B The information includes theory of operation and information on faulty assembly isolation Appendix A Manual Changes Appendix A contains manual changes and provides information for using this manual with 4338Bs manufactured before the printing date of the manual Appendix B Default Jumper and Switch Settings Appendix B describes the settings of the jumpers and switches on the 4338B A2 CPU Board Assembl
40. th flatcable 2 2110 0565 1 Fuse Holder 2110 0202 1 Fuse 0 25 A Slow Blow 230V 2110 0201 Fuse 0 5 A Slow Blow 115V 3 0515 1551 2 Screw M3 4 04338 00102 1 Chassis 5 2190 0054 1 Washer 2950 0054 1 Nut 1 Includes two sets of screw washer and nut 3 6 Assembly Replacement Table 3 6 Replaceable Mechanical Parts List 3 N koy O A 7 Hidden Hidden Reference Agilent Part Qty Description Designation Number 1 0515 2079 1 Screw M4 on the Chassis 2 04263 24001 2 Nut Rod for Transformer 2190 0586 2 Washer Spring M4 3 04263 00607 1 Plate Shield 4 04263 24002 2 Nut Rod for DC DC Conv 2190 0584 2 Washer Spring M3 5 0515 1550 7 Screw M3 for Al and A2 04339 24006 4 Standoff Hidden for Al 6 5040 3347 2 Plate Hidden Chassis Reverse side 0460 0616 150 mm x 2 Adhesive Tape for Plate 7 04263 07001 2 Gasket 0515 1550 4 Screw M3 8 0370 2862 1 Button Line Switch 04339 23001 1 Shaft Line Switch 0535 0081 1 Nut for Shaft 9 04339 25002 2 Support Line Switch Plate
41. ty service or repair this product must be returned to a service facility designated by Agilent Technologies Buyer shall prepay shipping charges to Agilent Technologies and Agilent Technologies shall pay shipping charges to return the product to Buyer However Buyer shall pay all shipping charges duties and taxes for products returned to Agilent Technologies from another country Agilent Technologies warrants that its software and firmware designated by Agilent Technologies for use with an instrument will execute its programming instruction when property installed on that instrument Agilent Technologies does not warrant that the operation of the instrument or software or firmware will be uninterrupted or error free Limitation Of Warranty The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside the environmental specifications for the product or improper site preparation or maintenance No other warranty is expressed or implied Agilent Technologies specifically disclaims the implied warranties of merchantability and fitness for a particular purpose Exclusive Remedies The remedies provided herein are buyer s sole and exclusive remedies Agilent Technologies shall not be liable for any direct indirect special incidental or consequential damages whether based on contract tort or a
42. umber prefix that is not listed on the title page This unlisted serial number prefix indicates the instrument is different from those described in this manual The manual for this new instrument may be accompanied by a yellow Manual Changes supplement or have a different manual part number This sheet contains change information that explains how to adapt the manual to the newer instrument In addition to change information the supplement may contain information for correcting errors Errata in the manual To keep this manual as current and accurate as possible Agilent Technologies recommends that you periodically request the latest Manual Changes supplement The supplement for this manual is identified by this manual s printing date and its part number both of which appear on the manual s title page Complimentary copies of the supplement are available from Agilent Technologies If the serial prefix or number of an instrument is lower than that on the title page of this manual see Appendix A Manual Changes For information concerning a serial number prefix that is not listed on the title page or in the Manual Change supplement contact the nearest Agilent Technologies office General Information 1 1 Required Equipment Table 1 1 lists the required equipment for adjusting and troubleshooting the 4338B Table 1 2 lists the required language extensions to be used with the adjustment program Table 1 1 Required Equipment
43. y The information is required when the A2 assembly is replaced viii Contents 1 General Information Introduction tz sc r e r a s it s st s s s ts e os t 1 1 Instruments Covered by This Manual 1 1 Required Equipment O 1 2 2 Adjustment Introduction 2 1 Safety Consideration nG 2 1 Required Equipment a a A 2 1 Adjustment Tools 2 2 2 2 A 2 2 Adjustable Components 2 7 sc c s c s o 2 2 Factory Selected Components 2 2 EEPROM Write Protect Switch AA 2 2 Related Adjustment 2 2 Adjustment Program AG 2 3 Program Installation 2 4 Making a Working Copy 2 4 Program Execution Ce e 2 4 Adjustment Procedure References t t t t t 2 5 Resistance Measurement Adjustment AG 2 5 Equipment AA 2 5 Setup 2 UA 2 5 3 Assembly Replacement Introduction 2 2 a 3 1 Ordering Information a 3 1 Restored Exchange Assemblies 2 2 2 2 a ee sc s c v 3 1 Replacing the A2 CPU Board Assembly GA 3 2 Replaceable Assembly List AA 3 2 Replaceable Mechanical Parts List a 3 5 Disassembly Procedures GA 3 9 Tools and Fasteners UA 3 9 Cover Removal AA 3 9 Al Main Board Removal _ _ 7 s s sc
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