Agilent Part No Microfiche Part No September
Certification
Safety Considerations
Safety Symbol Definitions
Symbol Description
Printing History
Table of Contents
Diagrams
Principles Of Operation
Replaceable Parts
Backdating
Scope Organization
Instrument Identification
Chapter Description
Introduction
Related Documents
Manual Revisions
Firmware Revisions
Change Sheet
Safety Considerations
Conventions
Electrostatic Discharge
Introduction
Tests
Test Equipment Required List of Equipment
Current-Monitoring Resistor
Electronic Load
Programming The Tests General Considerations
General Measurement Techniques
Performance Test Record Sheets
Programming Parameters
Operation Verification Tests
Performance Tests
Constant Voltage CV Tests
Constant Voltage CV Test Setup Verification
Constant Voltage CV Tests Action Normal Result
Voltage Programming and Readback Accuracy
CV Load Effect
CV Source Effect
CV Noise Pard
Transient Recovery Time
Transient Response Waveform Verification
Constant Current CC Tests
Constant Current CC Tests Action Normal Result
Current Programming and Readback Accuracy
CC Noise Pard
CC Load Effect
CC Source Effect
CC Load Effect Test Setup Verification
CC rms Noise Test Setup Verification
Averaging the CC Measurements
Performance Test Record Form
Test Facility
Results
Spec
Uncertainty
Vout 0.5mV Vout + 0.5mV 900 nV
Vout 1mV Vout + 1mV
Vout 1.7mV Vout + 1.7mV
Vout 2.3mV Vout + 2.3mV
Introduction Localizing the Problem
Troubleshooting
Chapter Organization
Topic Information Given
Troubleshooting Procedures Power-On Selftest
Test Equipment Required
FP ROM
EE Chksm
PRI Xram
PRI Iram
Troubleshooting Charts
Troubleshooting Test Points
Chart Trouble or Circuit
Bias and Reference Supplies
Overall Troubleshooting Sheet 1
Overall Troubleshooting Sheet 2
Overall Troubleshooting Sheet 3
Overall Troubleshooting Sheet 4
No Display Troubleshooting
OV Will Not Fire Troubleshooting
OV At Turn-On Troubleshooting
Output Held Low Troubleshooting Sheet 1
Output Held Low Troubleshooting Sheet 2
Output Held High Troubleshooting
DAC Circuits Troubleshooting
DAC Test Waveforms Troubleshooting
CV/CC DAC and Amplifier Circuit Troubleshooting
10. Serial Down Troubleshooting Sheet 1
10. Serial Down Troubleshooting Sheet 2
11. Secondary Interface Down Sheet 1 Troubleshooting
11. Secondary Interface Down Sheet 2 Troubleshooting
12. Slow Downprogramming Troubleshooting
CV/CC Status Annunciators Troubleshooting
A3 FET Board Troubleshooting
FET Troubleshooting Chart Procedure Result
Static Troubleshooting
Dynamic Troubleshooting
13. A3 FET Board Test Waveforms Troubleshooting
Signature Analysis Introduction
Allocate L$52 Output 705*IDN? Enter 705L$ Disp L$ 50 END
Agilent Technologies ,6681A,O,fA.01.05sA.01.04pA.0l.02
Pins Description
Front Panel Test Connector A1J3
Test Headers
Primary Interface SA Test
Valid A2U106 ROM Firmware Revision A.01.06
16. Signature Analysis Connections, Sheet 1 Troubleshooting
Valid A1U4 ROM Firmware Revision A.01.07
Secondary Interface SA Test
Valid A5U504 ROM Firmware Revision A.01.04
Post-Repair Calibration When Required
Calibration Password
Inhibit Calibration Jumper
Restoring Factory Calibration Constants
Initialization I or Factory Preset Replacement F?
Initialization I or Factory Preset Replacement F? F
Eeprom Initialization
Clear Screen
Case Else
END Select
Else
END if
Stop
Case
1530
Disassembly Procedures
Tools Required
Return
END
Top Cover
Removing Protective RFI Shield Galvanized Sheet Metal
Gpib Board
A4 AC Input Assembly
A5 DC Rail Assembly
A6 Bias Assembly
A3 FET Board
A10 Control Assembly
Front Panel Assembly
S1 Line Switch
A1 Front Panel Board
A1DSP1 LCD Display
A1G1 and A1G2 Rotary Controls
A1KPD Keypad
Output Bus Boards A7, A81 and A9 & Chassis Components
Page
19 -Inch Front Panel Frame Assembly Troubleshooting
20 -Inch Front Panel Frame Assembly Troubleshooting
21. Assembly A10, Exploded View Troubleshooting
22. Assembly A10, Exploded View 6680A, 6681A Troubleshooting
Page
24. Three-Phase Line Choke Subchassis Wiring Troubleshooting
25 Volt Fan Transformer Troubleshooting
A2 Gpib Board
Principles Of Operation
A1 Front Panel Assembly
A10 Control Board
Secondary Interface P/O A10 Board
AC Calibration of Imon
Principles Of Operation
A4 AC Input Board
A5 DC Rail Board
ST Stage of the FET H-Bridge Configuration
Output Circuits
Page
Assembly See
Reading the Tables
Part Reference Designators
Part Description Abbreviations
How to Order Parts
Main Chassis, Replaceable Parts
Ref. Desig Agilent Part No Description
SENSOR-MOISTURE TERM-BLK-4 POS Connector
BUS BAR Buss BAR Block BUSS/FET Block
Phase Line Choke
FAN Finger Guard
FAN-TUBEAXIAL
TRIM-SIDES
A1 Front Panel Board, Replaceable Parts
Front Panel Board LED Assy, Replaceable Parts
Mechanical Parts
DIO-SWITCHING
DIO-PWR Rect
CORE-SHLD-BEAD
CORE-MAGNETIC
Q301, 302, 303 1855-0859
Replaceable Parts
A4 AC Input Assembly, Replaceable Parts
10. A6 Bias Assembly, Replaceable Parts
FU-SUBMIN 4A
Heat SINK-TRANSISTOR 1854-0828 Assy
XFMR- Gpib
XFMR-BIAS
Heat SINK-LM317T Regulator Assy
Heat SINK-UA7805UC Regulator Assy
Wire KIT
12. A7 Fast Sense Assembly, Replaceable Parts
Fast Sense PC Assembly
Power Modfet
FU-SUBMIN 15A
FU-SUBMIN 7A
Xstr PNP
Replaceable Parts
C588 0160-4799 CAP 2.2pF 5% C589 6680A, 6681A
DIO GEN PRP
Phone Receptable
FET P-CHAN
NETWORK-RES SIP
Replaceable Parts
Replaceable Parts
RES 45K
RES2.2M
RES 10K
IC-REG TL7702BCP
IC OP AMP
IC-VOLTAGE REG
PRGMD-IC, SEC
IC MC74HC138N
IC-CONVERTER,DIA
IC-LINEAR
Summary of Chapter Contents Function Description See
Diagrams
Signal Name Mnemonics Description A0--A15
AD O--AD7
ANA0--ANA7
D0D7
AC Input Board
DC Rail Board
Bias Board
A3 FET Board
A10 Control Board
CV Control Sheet
CC Control Sheet
General Schematic Notes
General Schematic Notes
DP Control Sheet
Common
Test Point Waveforms for Table Diagrams
Circuit Board Cabling Diagram Diagrams
Page
A1 Front Panel Board, Schematic Diagram
LED Board, Component and Test Point Location
A2 Gpib Board, Component Location
A2 Gpib Board, Schematic Diagram
A3 FET Board, Component and Test Point Location
10. A3 FET Board, Schematic Diagram sheet 1
10. A3 FET Board, Schematic Diagram sheet 2
11. A4 AC Input Board, Component and Test Point Location
12. A4 AC Input Board, Schematic Diagram
13. A5 DC Rail Board, Component and Test Point Location
14. A5 DC Rail Board, Schematic Diagram
15. A6 Bias Board, Component and Test Point Location
16. A6 Bias Board, Schematic Diagram Sheet 1of
16. A6 Bias Board, Schematic Diagram Sheet 2
17. Power Mesh, Schematic Diagram, Models 6680A, 6681A Only
Page
19. A7 Snubber Board, Component Location
21. A8 Fast Sense Board, Component Location
23. A9 Down Programming/Slow Sense, Component Location
24. A9 Down Programming/Slow Sense, Schematic Diagram
25. A10 Control Board, Component and Test Point Location
26. A10 Control Board, Schematic Diagram Sheet 1
26. A10 Control Board, Schematic Diagram Sheet 2
26. A10 Control Board, Schematic Diagram Sheet 3
26. A10 Control Board, Schematic Diagram Sheet 4
Serial Numbers Change Model 6680A Model 6683A
Model 6681A Model 6684A
Model 6682A
Backdating
-9 A5 DC Rail Board
-14 Al0 Control Board
-8 A4 AC Input Board
-6 A2 Gpib Board
Table A-1. A2 Gpib Parts List
Ref Desig Agilent Part No Description
IC Drom Gpib
Figure A-1. A2 Gpib Component Parts List Backdating
Index
Index
Error code
Message
104
Signal name
Troubleshooting
17 
18
16
15