Troubleshooting; Introduction - Keithley 2002 Repair Manual

WARNING
The information in this section is in-
tended for qualified service personnel.
Some of these procedures may expose
you to hazardous voltages. Do not per-
form these hazardous procedures unless
you are qualified to do so.
2.1

Introduction

This section of the manual will assist you in troubleshooting
the Model 2002. Included are self-tests, test procedures,
troubleshooting tables, and circuit descriptions. It is left to
the discretion of the repair technician to select the appropri-
ate tests and documentation needed to troubleshoot the in-
strument.
This section is arranged as follows:
2.2 Repair considerations: Covers some considerations
that should be noted before making any repairs to the
Model 2002.
2.3 Power-on test: Describes the tests that are performed
on its memory elements each time the instrument is
turned on.
2.4 Front panel tests: Provides the procedures to test the
functionality of the front panel keys and the display.

Troubleshooting

2.5 Diagnostics: Explains how to use the Diagnostics test
mode of the Model 2002. In general, Diagnostics
locks-up the instrument in various states of operation.
With the instrument in a static state, you can then
check the state of the various logic levels on the con-
trol registers and signal trace through the unit.
2.6 Control register bit patterns: Provides shift register
bit patterns for the basic measurement functions and
ranges.
2.7 Display board checks: Provides display board checks
that can be made if Front Panel Tests fail.
2.8 Power supply checks: Provides power supply checks
that can be made if the integrity of the power supply is
questionable.
2.9 Principles of operation: Provides support documen-
tation for the various troubleshooting tests and proce-
dures. Included is some basic circuit theory for the
display board and power supply, and support docu-
mentation for Built-in tests.
2.10 Built-in test overview: Summarizes the Built-in tests,
which can be used to test and exercise the various cir-
cuits on the digital board, analog board and A/D con-
verter boards.
2.11 Built-in test documentation: Provides a detailed
analysis of each Built-in test.
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