To Check a rig:-

1. Visual check of the antenna, cable wiring connectors mic - anything obious.

2. VSWR check - this will confirm that the cable and antenna is ok, and that the radio is trasmitting the correct power.

3. Still a problem, the unit is pulled and put on a bench and connect to a service monitor. Power, deivation receiver sensitiity et is checked.

The most common problem is always connecotrs, cable run and antennas


(Im a radio tech)