Batboard

I have a VHF maxtrac 16 pin unit. The unit has worked fine but now there is no audio and the busy light stays on as if in constant monitor. The jumper pin is in on the 16 pin connector for audio. What is the most likely place to look? Front panel? Logic board?

Tnx, Buddy

Do any of the buttons work? Does it beep when you press a button?

The channel up/down buttons work. No other buttons seem to work. Busy light flashes all the time, monitor light is on.
No audio.

Thanks

If the accy. plug is wired properly, but still no audio, check the audio P.A stage, as this is a 2-stage audio amp.
The monitor light will be lit if the rcve PL is active, and no mic is in the HUB, or the jumper plug for this is removed from the mic. receptacle.

The MON. light symbolizes no active PL/DPL for the rcve function(as set through RSS).

Is the radio able to properly receive a on-channel signal?
If no, then check the 2nd oscillator crystal(Y52), and see if it is at 44.645Mhz.

If the RX frequency sounds distorted or off-channel, then I would suspect the 2nd oscillator crystal to be bad, as this will cause a deaf receiver function.

If you can hold the MON. button and get sound, your ausio/receiver stage is functioning, you simply need to dig a little deeper to find and isolate the problem.

Use a sniffer probe in the receiver, and check for signals that should be present before digging deeper.

Check your reference oscillator for 16.8 Mhz signal also.

Simple tests can be done without removing a single screw...check the above first and then pop the hood.

Good luck!
Ernest
A.E.C