Watkins-Johnson Company WJ-8718-19/FE Instruction Manual page 169

MAINTENANCE WJ-8718-19/FE HF RECEIVER
4.3.4 MODULE TROUBLESHOOTING PROCEDURES
Module troubleshooting procedures consist of checkout, fault-isolation and
repair information necessary to restore a malfunctioning module to normal operation.
Troubleshooting information provided in this paragraphs consists of the following
categories:
1. Module checkout procedures to verify module fault
symptoms.
2. Fault isolation tables to help isolate defective
components on the modules. Semiconductor voltage
tables are also provided to help locate defective
transistors and integrated circuits.
3. A Parts Replacement Guide, Paragraph 4.3.5, to assist in
repairing a defective module.
In addition to using the information provided in this paragraph, reference
to the Circuit Description in Section III and Schematic Diagrams in Section VI is
essential for efficient module troubleshooting.
4.3.4.1 Procedure Guidelines
To properly check-out and troubleshoot a defective module, the following
guide lines should be utilized:
1. Allow the test equipment a 30 minute warm-up before
any check out.
2. Refer to the Testing and Troubleshooting paragraph for
the desired module. Configure the receiver and test
equipment as stated in the Checkout Procedure for the
desired module.
3. Perform the Checkout Procedure in the sequence given.
If any desired result is not obtained, refer to the Fault
Isolation Table for the module to locate the defective
component.
4. Refer to the Parts Replacement Guide, Paragraph 4.3.5,
to assist in replacing any components found to be
defective. Following component replacement, re-perform
the Module Checkout Procedure. If the module still
fails, additional troubleshooting using the Circuit
Descriptions in Section III and Schematic Diagrams in
Section VI is necessary.
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