Service manual

5
Table Of Contents
Introduction ............................................................................................................................................................................ 7
Scope .................................................................................................................................................................................... 7
Related Documents ............................................................................................................................................................... 7
Firmware Revisions .............................................................................................................................................................. 7
Manual Revisions.................................................................................................................................................................. 7
Safety Considerations ........................................................................................................................................................... 8
Disassembly Procedures ......................................................................................................................................................... 9
Introduction........................................................................................................................................................................... 9
Fans....................................................................................................................................................................................... 9
Front Panel............................................................................................................................................................................ 9
GPIB Board ........................................................................................................................................................................ 10
Keypad................................................................................................................................................................................ 10
LCD Display and Window.................................................................................................................................................. 10
Line Switch......................................................................................................................................................................... 11
Modules .............................................................................................................................................................................. 11
Power Transistors (located on modules)............................................................................................................................. 11
Transformer (on mainframe)............................................................................................................................................... 12
Troubleshooting .................................................................................................................................................................... 13
Introduction......................................................................................................................................................................... 13
Test Equipment Required ................................................................................................................................................... 13
Electrostatic Discharge (ESD) Protection........................................................................................................................... 13
Overall Troubleshooting Procedures .................................................................................................................................. 15
Selftest Sequence and Error Messages................................................................................................................................ 15
Primary Circuits.............................................................................................................................................................. 19
Secondary Circuits.......................................................................................................................................................... 19
Test Points ...................................................................................................................................................................... 21
Signature Analysis .............................................................................................................................................................. 24
Firmware Revisions ........................................................................................................................................................ 24
Test Header Jumper Positions......................................................................................................................................... 25
Test Setup for Signature Analysis................................................................................................................................... 25
GPIB Board Troubleshooting Setup ............................................................................................................................... 26
Load Module Troubleshooting Setup ............................................................................................................................. 26
DAC Circuits Troubleshooting (Figure 3-3)....................................................................................................................... 39
Slew Circuit Troubleshooting (Figure 3-4)......................................................................................................................... 41
CC/CV CONTROL CIRCUIT TROUBLESHOOTING (Figure 3-5)................................................................................ 42
Input Power Stages Troubleshooting (Figure 3-6).............................................................................................................. 47
Transient Generator Troubleshooting (Figure 3-7)............................................................................................................. 47
General Troubleshooting ................................................................................................................................................ 47
Transient Generator Frequency....................................................................................................................................... 47
Toggle or Pulse Modes ................................................................................................................................................... 50
Trigger Circuit Troubleshooting (Figure 3-8)..................................................................................................................... 51
AC Line Triggers............................................................................................................................................................ 51
Internal Timer Triggers................................................................................................................................................... 51
Level Triggers (*TRG and TRIG command).................................................................................................................. 52
Group Enable Trigger (GET function)............................................................................................................................ 52
External Triggers ............................................................................................................................................................ 52
Overcurrent Circuit Troubleshooting (Figure 3-9).............................................................................................................. 54
Overpower Circuit Troubleshooting (Figure 3-10) ............................................................................................................. 55
Fan Speed Control Troubleshooting (Figure 3-11) ............................................................................................................. 56