Batboard

I recently purchased 5 HT1000 bodies, 4 of which are DN and the one in question is BN. The BN has an issue where the incoming RF singals are extremely low volume on T/Rx channels and no volume at all on Rx Only channels. I know it's not the speaker because I have the TPT hack on this unit, (and my DNs too.), and the TPT beeps are full volume. I presume this is due to a pinched cable within the unit, as a few light taps on the front of the radio temporarily fix the issue.

Am I right? Wrong? What should I do to fix this?

P.S. The TPT seems to be much quieter on the DNs than the BN. How can I make the TPT full volume on the DNs?