Agilent Technologies 6680A User Manual Page 1

SERVICE MANUALGPIB DC Power SuppliesAgilent Series 668xAFor instruments with Serial Numbers:Agilent Model 6680A: US36480101 and Above *Agilent Model 6

Verification 11 2 Verification Introduction This chapter provides test procedures for checking the operation of Agilent Series 668xA power supplie

102 Replaceable PartsTable 5-10. A6 Bias Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR842 0698-6360 RES 10K .1%R

Replaceable Parts 103Table 5-11. A7 Snubber Assembly, Replaceable PartsRef. Desig. Agilent Part No. DescriptionELECTRICAL PARTSC910, 911, 912, 9136

104 Replaceable PartsTable 5-13. A9 Down Programmer/Slow Sense, Replaceable PartsRef. Desig. Agilent Part No. DescriptionELECTRICAL PARTSC950, 951

Replaceable Parts 105Table 5-14. A10 Control Assembly, Replaceable PartsRef. Desig. Agilent Part No. DescriptionELECTRICAL PARTSC500, 501, 502 0180

106 Replaceable PartsTable 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionC588 0160-4799 CAP 2.2p

Replaceable Parts 107Table 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionC639 0160-4795 CAP 4.7p

108 Replaceable PartsTable 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR506 0757-0289 RES 13.3

Replaceable Parts 109Table 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR570, 580 0757-0424 RES

110 Replaceable PartsTable 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR624 0757-0453 RES 30.1

Replaceable Parts 111Table 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR6666680A 0698-8913 RES

12 Verification Table 2-1. Test Equipment Required Type Required Characteristics Recommended Model Digital Voltmeter1 Resolution: 10 nV @ 1V A

112 Replaceable PartsTable 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR6846680A 0757-0280 RES

Replaceable Parts 113Table 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR7096680A 0757-0468 RES

114 Replaceable PartsTable 5-14. A10 Control Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionU506 5080-2305 PRGMD-IC

Diagrams 1156DiagramsIntroductionThis chapter contains drawings and diagrams for troubleshooting and maintaining Agilent Series 668xA Power Supplies

116 DiagramsTable 6-2. Signal Name MnemonicsMnemonic Description Mnemonic DescriptionA(0)--A(15) Address lines MSRQ Microprocessor service requestA

Diagrams 117Table 6-3. Test PointsTEST POINT No. & Loc. Signal Tested Measurement and ConditionsA2 GPIB BOARD J106-4Primary/chassis ground Conn

118 DiagramsTable 6-3. Test Points (continued)TEST POINT No. & Loc. Signal Tested Measurement and ConditionsBias Board (continued)U308-1PREF+2.

Diagrams 119Table 6-3. Test Points (continued)TEST POINT No. & Loc. Signal Tested Measurement and ConditionsA10 Control Board (continued)U600-1

120 DiagramsFigure 6-1. Test Point Waveforms for Table 6-3

Diagrams 121Figure 6-2. Circuit Board Cabling Diagram

Verification 13 Programming The Tests General Considerations Procedures are given for programming these tests either from the front panel keypad or

122 DiagramsFigure 6-3. A1 Front Panel Board, Component and Test Point Location

Figure 6-4. A1 Front Panel Board, Schematic Diagram

Figure 6-5. LED Board, Component and Test Point LocationFigure 6-6. LED Board, Schematic Diagram

Figure 6-7. A2 GPIB Board, Component Location

23416578Figure 6-8. A2 GPIB Board, Schematic Diagram

Figure 6-9. A3 FET Board, Component and Test Point Location

Figure 6-10. A3 FET Board, Schematic Diagram (sheet 1 of 2)

Figure 6-10. A3 FET Board, Schematic Diagram (sheet 2 of 2)

Figure 6-11. A4 AC Input Board, Component and Test Point Location9101112

Figure 6-12. A4 AC Input Board, Schematic Diagram

14 Verification Operation Verification Tests Table 2-3 lists the requirements for operation verification, which is a subset of the performance tes

Figure 6-13. A5 DC Rail Board, Component and Test Point Location1314

Figure 6-14. A5 DC Rail Board, Schematic Diagram1314

Figure 6-15. A6 Bias Board, Component and Test Point Location1516171819

Figure 6-16. A6 Bias Board, Schematic Diagram (Sheet 1of 2)19

Figure 6-16. A6 Bias Board, Schematic Diagram (Sheet 2 of 2)15161718

Figure 6-17. Power Mesh, Schematic Diagram, Models 6680A, 6681A Only

Figure 6-18. Power Mesh, Schematic Diagram Models 6682A, 6683A, 6684A Only

Figure 6-19. A7 Snubber Board, Component LocationFigure 6-20. A7 Snubber Board, Schematic Diagram

Figure 6-21. A8 Fast Sense Board, Component LocationFigure 6-22. A8 Fast Sense Board, Schematic Diagram

Figure 6-23. A9 Down Programming/Slow Sense, Component Location

Verification 15 Figure 2-1. Constant Voltage (CV) Test Setup

Figure 6-24. A9 Down Programming/Slow Sense, Schematic Diagram

Figure 6-25. A10 Control Board, Component and Test Point Location475544414246484363535150494538366062615954525758566437213622203940

Figure 6-26. A10 Control Board, Schematic Diagram (Sheet 1 of 4)21222036373863

Figure 6-26. A10 Control Board, Schematic Diagram (Sheet 2 of 4)644039

Figure 6-26. A10 Control Board, Schematic Diagram (Sheet 3 of 4)56616058575954525350514962556566

Figure 6-26. A10 Control Board, Schematic Diagram (Sheet 4 of 4)48434742413946454440

Backdating 149ABackdatingManual backdating describes changes that must be made to this manual for power supplies whose serial numbers are lowerthan

150 BackdatingIn Table 5-9 A5 DC Rail BoardDELETEC418, 0.022uF 250VAC "Y" rated P/N 0160-4048Fuse Clips, REF F420 & 421 1/4" P/N

Backdating 151Table A-1. A2 GPIB Parts ListRef Desig. Agilent Part No. DescriptionELECTRICAL PARTSC102-105 0160-4822 Capacitor 1000pF 5%C106 0180-01

152 BackdatingTable A-1. A2 GPIB Parts List (continued)Ref Desig. Agilent Part No. DescriptionELECTRICAL PARTSTB101 0360-2312 Terminal block (digita

16 Verification Table 2-4. Constant Voltage (CV) Tests Action Normal Result Voltage Programming and Readback Accuracy This test verifies that t

Backdating 153Figure A-1. A2 GPIB Component Parts List

Index 155IndexAA1 Front Panel Board, test header ...

156 IndexCV source effect, defined...

Index 157UART PARITY ...

158 IndexMnemonics signal names ...

Index 159load ...

160 IndexTroubleshootingtest points...

Verification 17 Table 2-4. Constant Voltage (CV) Tests (continued) Action Normal Result CV Source Effect (cont) 2 Set the transformer to the n

18 Verification Table 2-4. Constant Voltage (CV) Tests (continued) Action Normal Result Transient Recovery Time This test measures the time requ

Verification 19 Constant Current (CC) Tests Test Setup Connect the appropriate current monitoring resistor (see Table 2-l) as shown in Fig. 2-3. Th

20 VerificationTable 2-5. Constant Current (CC) Tests (continued)Action Normal ResultCC Noise (PARD) (cont)2 Measure the residual noise on the DVM

2CERTIFICATIONAgilent Technologies certifies that this product met its published specifications at time of shipment from the factory. AgilentTechnolog

Verification 21Table 2-5. Constant Current (CC) Tests (continued)Action Normal ResultCC Source EffectThis test measures the change in output curren

22 VerificationFigure 2-3. CC Load Effect Test Setup

Verification 23Figure 2-4. CC rms Noise Test Setup

24 VerificationAveraging the CC MeasurementsThe CC Load Effect and CC Source Effect tests measure the dc regulation of the power supply's outp

Verification 25Table 2-6. Performance Test Record FormTest Facility:__________________________________________ Report No._________________________

26 VerificationTable 2-7. Performance Test Record for Agilent Model 6680AMODEL Agilent _____________Report No.______________ Date_________________

Verification 27Table 2-7. Performance Test Record for Agilent Model 6681AMODEL Agilent_____________Report No.______________ Date__________________

28 VerificationTable 2-7. Performance Test Record for Agilent Model 6682AMODEL Agilent_____________Report No.______________ Date__________________

Verification 29Table 2-7. Performance Test Record for Agilent Model 6683AMODEL Agilent_____________Report No.______________ Date__________________

30 VerificationTable 2-7. Performance Test Record for Agilent Model 6684AMODEL Agilent_____________Report No.______________ Date__________________

3SAFETY CONSIDERATIONSGENERAL. This is a Safety Class 1 instrument (provided with terminal for connection to protective earth ground).OPERATION. BEF

Troubleshooting 313Troubleshooting Shock Hazard: Most of the procedures in this chapter must be performed with power applied and protective cove

32 TroubleshootingTest Equipment RequiredTable 3-1. Test Equipment RequiredEquipment Purpose Recommended ModelLogic Probe To check states of data l

Troubleshooting 33Table 3-2. Selftest Error Codes/MessagesCode and/orMessageDescription Probable Cause Selftest ErrorCodes/MessagesEl FP RAM Front

34 TroubleshootingTroubleshooting ChartsFigure 3-1 gives overall troubleshooting procedures to isolate the fault to a circuit board or particular ci

Troubleshooting 35Figure 3-1. Overall Troubleshooting (Sheet 1 of 4)

36 TroubleshootingFigure 3-1. Overall Troubleshooting (Sheet 2 of 4)

Troubleshooting 37Figure 3-1. Overall Troubleshooting (Sheet 3 of 4)

38 TroubleshootingFigure 3-1. Overall Troubleshooting (Sheet 4 of 4)

Troubleshooting 39Figure 3-2. No Display Troubleshooting

40 TroubleshootingFigure 3-3. OV Will Not Fire Troubleshooting

4 Safety Symbol DefinitionsSymbol Description Symbol DescriptionDirect current Terminal for Line conductor on permanentlyinstalled equipmentAlternatin

Troubleshooting 41Figure 3-4. OV At Turn-On Troubleshooting

42 TroubleshootingFigure 3-5. Output Held Low Troubleshooting (Sheet 1 of 2)

Troubleshooting 43Figure 3-5. Output Held Low Troubleshooting (Sheet 2 of 2)

44 TroubleshootingFigure 3-6. Output Held High Troubleshooting

Troubleshooting 45Figure 3-7. DAC Circuits Troubleshooting

46 TroubleshootingFigure 3-8. DAC Test Waveforms

Troubleshooting 47Figure 3-9. CV/CC DAC and Amplifier Circuit Troubleshooting

48 TroubleshootingFigure 3-10. Serial Down Troubleshooting (Sheet 1 of 2)

Troubleshooting 49Figure 3-10. Serial Down Troubleshooting (Sheet 2 of 2)

50 TroubleshootingFigure 3-11. Secondary Interface Down (Sheet 1 of 2)

5 Table of ContentsIntroduction ...

Troubleshooting 51Figure 3-11. Secondary Interface Down (Sheet 2 of 2)

52 TroubleshootingFigure 3-12. Slow Downprogramming Troubleshooting

Troubleshooting 53CV/CC Status Annunciators TroubleshootingWhen troubleshooting the CV/CC status annunciators or status readback circuits, first mea

54 TroubleshootingTable 3-4. FET Troubleshooting Chart (continued)Procedure ResultDynamic Troubleshooting1. Turn off the power supply and remove t

Troubleshooting 55Figure 3-13. A3 FET Board Test Waveforms

56 TroubleshootingSignature AnalysisIntroductionThe easiest and most efficient method of troubleshooting microprocessor-based instruments is with si

Troubleshooting 57Test HeadersThe power supply has two test headers as shown in Figure 3-15, each with a jumper that can be moved to differentpositi

58 TroubleshootingTable 3-5. Primary Interface SA TestDescription: These signatures check some primary interface circuits on the Systems Supply A2

Troubleshooting 59Figure 3-16. Signature Analysis Connections, (Sheet 1 of 2)

60 TroubleshootingFigure 3-16. Signature Analysis Connections, (Sheet 2 of 2)Table 3-6. Front Panel SA TestDescription: These signatures check fro

6Post-Repair Calibration...

Troubleshooting 61Table 3-7. Secondary Interface SA TestDescription: These signatures check the secondary microprocessor A5U504.Valid A5U504 ROM Fi

62 TroubleshootingPost-Repair CalibrationWhen RequiredCalibration is required annually and also whenever certain components are replaced. If compone

Troubleshooting 63EEPROM InitializationEEPROM AlU6 on the A1 Front Panel Board stores the supply's GPIB address, model number, and constants re

64 Troubleshooting10 ! Program to initialize EPROM or move factory preset data in 668xA20 ! power supplies.30 ! RE-STORE " INIT_668X"40 !

Troubleshooting 65510 DATA 115,30,20,1,127,.002701,.2,.00042,10.25520 !530 Eprom_data_6684: ! ! EEPROM data for 6684A540 DATA 93,74,41,0,83,0,29,70

66 Troubleshooting1020 GOSUB Ps_error ! Error if passcode is not "0"!1030 IF Err THEN1040 OUTPUT @Ps;"*IDN?" ! Get data fro

Troubleshooting 671530 CLEAR SCREEN1540 PRINT "This program should ONLY be completed if your power supply”1550 PRINT "EEPROM has been re

68 Troubleshooting2010 IF Err THEN2020 PRINT "An error occurred during the EEPROM read/write, Check for"2030 PRINT "programmi

Troubleshooting 69Top Cover1. Remove the four screws that secure the carrying straps (two TORX 20 screws on each side). These same screws securethe

70 TroubleshootingA4 AC Input AssemblyTo remove the A4 AC Input Board first remove the GPIB board then disconnect these cables from the following co

Introduction 7 1 Introduction Scope Organization This manual contains information for troubleshooting and repairing to the component level Agilent

Troubleshooting 71A10 Control Assembly Disconnect the cables from the following connectors at the A10 DC RAIL board:1. Disconnect the ribbon cable

72 TroubleshootingA1DSP1 LCD Display1. Remove the A1 Front Panel Board as described in that procedure.2. Remove the nuts securing the LCD display

Troubleshooting 73Figure 3-18. Component Locations (Top Cover and RFI Shield Removed)

74 TroubleshootingFigure 3-19. 5-Inch Front Panel Frame Assembly

Troubleshooting 75Figure 3-20. 3-Inch Front Panel Frame Assembly

76 TroubleshootingFigure 3-21. Assembly A10, Exploded View

Troubleshooting 77Figure 3-22. Assembly A10, Exploded View (6680A, 6681A)

78 TroubleshootingFigure 3-23. Assembly A10, Exploded View (6682A, 6683A, 6684A)

Troubleshooting 79Figure 3-24. Three-Phase Line Choke Subchassis Wiring

80 TroubleshootingFigure 3-25. 24 Volt Fan Transformer

Introduction 8 Related Documents Change Sheet There may or may not be a Manual Change sheet included with this manual (see Manual Revisions). If o

Principles Of Operation 814Principles Of OperationIntroductionFigure 4-3 (at the end of this chapter) is a block diagram showing the major circuits

82 Principles Of Operation A digital control interface on the A2 GPIB Board provides the following power supply functions:• Relay link.• Digital 1/0

Principles Of Operation 83 The Secondary Microprocessor translates serial data received from the A2 board into parallel 12 bit data. The data bus is

84 Principles Of Operationany value of load impedance. Switching between CV and CC is done automatically by the CV/CC control circuits at avalue of

Principles Of Operation 85 A4 AC Input Board The A4 Input Board contains the Inrush-Current Limit relay (K401), Main Power Relay (K402), current-li

86 Principles Of Operation Figure 4-2. 1ST Stage of the FET H-Bridge Configuration Output Circuits The output circuits include the following cir

Principles Of Operation 87Figure 4-3. Agilent Series 668xA Power Supply, Block Diagram

Replaceable Parts 895Replaceable PartsINTRODUCTIONChapter OrganizationThis section lists the replaceable electrical and mechanical parts for the Agi

90 Replaceable PartsHow to Order PartsYou can order parts from your local Agilent Technologies, Inc. Sales and Support Office (see the list of offic

Replaceable Parts 91Table 5-3. Main Chassis, Replaceable PartsRef. Desig. Agilent Part No. DescriptionC9076680A 0180-4516 CAP 33000uF 7.5V6681A 018

Introduction 9Safety ConsiderationsThis power supply is a Safety Class I instrument, which means it has a protective earth terminal. This terminal mu

92 Replaceable PartsTable 5-3. Main Chassis, Replaceable Parts (continued)Ref. Desig. Agilent Part No. Description2110-0910 FUSE (see 5060-3513 )21

Replaceable Parts 93Table 5-3. Main Chassis, Replaceable Parts (continued)Ref. Desig. Agilent Part No. Description1400-0611 CABLE CLAMP (GPIB/FAN)5

94 Replaceable PartsTable 5-4. A1 Front Panel Board, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionS1 3101-3088 Line switchV

Replaceable Parts 95Table 5-6. A2 GPIB Board, Replaceable Parts (see Note)Ref. Desig. Agilent Part No. DescriptionELECTRICAL PARTSC122 0180-4606Cap

96 Replaceable PartsTable 5-7. A3 FET Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionC244, 245 0160-6806 CAP .luF 4

Replaceable Parts 97Table 5-7. A3 FET Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionQ301, 302, 303, 304 1855-0859

98 Replaceable PartsTable 5-7. A3 FET Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR271 0757-0200 RES 5.62K 1%R27

Replaceable Parts 99Table 5-7. A3 FET Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionR383 0757-0442 RES 10K 1% .125

100 Replaceable PartsTable 5-9. A5 DC Rail Assembly, Replaceable PartsRef. Desig. Agilent Part No. DescriptionELECTRICAL PARTSC418 0160-4048 CAP 0.

Replaceable Parts 101Table 5-10. A6 Bias Assembly, Replaceable Parts (continued)Ref. Desig. Agilent Part No. DescriptionC823 0180-4131 CAP 4.7uF 35