Troubleshooting is done on a faulty power amplifier. The steps to determine if a power amplifier is faulty and how
to troubleshoot it are as follows:
When a power amplifier is received from unit maintenance, inspect it for damage. Repair any
damage before proceeding with testing. See section IV if repairs are necessary.
Verify the symptom.
Perform the operational check in paragraph 5-10. This will direct you to the
correct troubleshooting flowchart or identify the fault.
Troubleshoot the power amplifier using the flowchart.
It will identify the defective module or
Replace the defective module or component.
Follow the procedures in section IV.
Verify the repair.
Repeat the operational check in paragraph 5-10 that failed. If it passes, then
continue with the rest of the operational check. When the operational check is passed, the power
amplifier can be returned for use.
5-12. TEST PRECAUTIONS AND NOTES.
Set the test power supply to OFF before connecting or disconnecting a test setup. Current
capacities are large enough to cause personal injury. Equipment can also be damaged if care is
High voltage (200 V dc) is present at several places within the power amplifier. Use caution when
connecting the test setup and taking measurements to avoid personal injury.
High RF energy (50 watts) is present at J1 and several places within the power amplifier when the
handset PTT switch is pressed. Use caution to avoid personal injury.
Static electricity and stray voltages can damage the decoder control (6A2). Use an antistatic
pad on the work surface and wear a grounded wrist strap when troubleshooting.
High voltage (200 V) and high RF energy (50 watts) is present in the power amplifier during
testing. Do not disassemble with power applied to the power amplifier.
The Principles of Operation section, functional block diagrams, and figure FO-16 can be used to
help fault isolate any unusual problems that might not be covered in the troubleshooting