Introduction; Safety Considerations; Repair Considerations - Keithley 2430 Service Manual

4-2 Troubleshooting

Introduction

This section of the manual will assist you in troubleshooting and repairing the Model 2430.
Included are self-tests, test procedures, troubleshooting tables, and circuit descriptions. Note
that disassembly instructions are located in Section 5, and component layout drawings are at the
end of Section 6.

Safety considerations

WARNING

Repair considerations

Before making any repairs to the Model 2430, be sure to read the following considerations.
CAUTION
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The information in this section is intended for qualified service personnel
only. Do not perform these procedures unless you are qualified to do so.
Some of these procedures may expose you to hazardous voltages that could
cause personal injury or death. Use caution when working with hazardous
voltages.
Be sure to observe the following precautions regarding heat sink cool-down
time and capacitor voltage bleed-down time:
Heat sink cool-down time: five minutes to 70°C, 15 minutes to 50°C.
Capacitor voltage bleed-off time: two minutes to 50V, five minutes to 5V.
The PC-boards are built using surface mount techniques and require spe-
cialized equipment and skills for repair. If you are not equipped and/or
qualified, it is strongly recommended that you send the unit back to the fac-
tory for repairs or limit repairs to the PC-board replacement level. Without
proper equipment and training, you could damage a PC-board beyond re-
pair.
Repairs will require various degrees of disassembly. However, it is recommended that
the Front Panel Tests be performed prior to any disassembly. The disassembly instruc-
tions for the Model 2430 are contained in Section 5 of this manual.
Do not make repairs to surface mount PC-boards unless equipped and qualified to do so.
(See previous CAUTION.)
When working inside the unit and replacing parts, adhere to the handling precautions
and cleaning procedures explained in Section 5.
Many CMOS devices are installed in the Model 2430. These static-sensitive devices
require special handling as explained in Section 5.
Whenever a circuit board is removed or a component is replaced, the Model 2430 must
be recalibrated. See Section 2 for details on calibrating the unit.