6
Secondary Interface Troubleshooting................................................................................................................................. 41
Voltage and Current DAC...............................................................................................................................................41
Readback DAC Circuits..................................................................................................................................................43
Readback Multiplexer (U20):......................................................................................................................................... 43
Signature Analysis.............................................................................................................................................................. 45
Primary SA..................................................................................................................................................................... 45
Front Panel SA................................................................................................................................................................45
Secondary SA................................................................................................................................................................. 46
Power Section Troubleshooting..........................................................................................................................................51
Main Troubleshooting Setup...........................................................................................................................................52
Troubleshooting No-Output Failures..............................................................................................................................53
Power Section Blocks..................................................................................................................................................... 54
Troubleshooting AC-Turn-On Circuits...........................................................................................................................57
Troubleshooting DC-To-DC Converter..........................................................................................................................57
Troubleshooting Bias Supplies....................................................................................................................................... 58
Troubleshooting Down Programmer...............................................................................................................................61
Troubleshooting CV Circuit........................................................................................................................................... 61
Troubleshooting CC Circuit............................................................................................................................................62
Troubleshooting OVP Circuit.........................................................................................................................................62
Troubleshooting PWM & Clock.....................................................................................................................................63
Principles of Operation........................................................................................................................................................ 65
Introduction.........................................................................................................................................................................65
GPIB Board........................................................................................................................................................................ 65
Primary Microprocessor................................................................................................................................................. 65
Address Switches...........................................................................................................................................................65
EEPROM........................................................................................................................................................................ 67
Isolation.......................................................................................................................................................................... 67
Secondary Microprocessor............................................................................................................................................. 67
Digital-to-Analog Converters..........................................................................................................................................67
Analog Multiplexer.........................................................................................................................................................67
Status Inputs....................................................................................................................................................................67
Front Panel Board............................................................................................................................................................... 68
Address Latches and Decoders.......................................................................................................................................68
Volts and Amps Output Ports and Displays....................................................................................................................68
RPG and Latches............................................................................................................................................................ 68
Front-Panel Switches and Input Port...............................................................................................................................68
Mode Indicators.............................................................................................................................................................. 70
OVP Adjust Control........................................................................................................................................................70
Power Clear.................................................................................................................................................................... 70
Power Mesh and Control Board..........................................................................................................................................70
Overview.........................................................................................................................................................................70
Power Mesh.................................................................................................................................................................... 71
Control Board................................................................................................................................................................. 73
Replaceable Parts..................................................................................................................................................................79
Introduction.........................................................................................................................................................................79
Ordering Information..........................................................................................................................................................80
Component Location and Circuit Diagrams.................................................................................................................... 101