PRC77 no audio from mic or speaker

[Jeepsinker]

So I received the battery adapter from Brooke at PRC68.com yesterday, picked up some good fresh Duracells today and powered up my 77 off of the vehicle mount for the first time today. I am getting zero audio out of either of my H250 handsets ( one of which is brand new) or either of my external speakers. I do get audio (static) out of the speaker on the AM2060 base when I power it up that way, but still get no audio out of an external speaker if I hook one up while the radio is on the base. Looking at the guts of the radio, it would appear as if the obvious culprit might be the A55 receiver audio module. Any other common causes of this? I can't find any broken wires or loose solder joints, and I did clean the handset and transceiver side contacts with an eraser. I also disassembled the cable ends on both handsets and checked for broken wires there and found none. It would be great if I could just drop in a replacement A55 module and be good to go, but things are never that easy.

 

[m38inmaine]

Make sure that you replace the "cap" back on the radio "power" connector where your power cable went over to the amp. If that protective cap is not installed on the 77 the radio won't work. If you are getting static on the amp but not the 77 stand alone, changing the module won't fix anything. Also try cleaning the radio audio connectors with a pencil eraser.
Also, if you are trying to use a LS-454 external speaker with the 77 you will need to re-wire the speaker connector. You will need to move the connection on pin E to pin B.

 

[Jeepsinker]

The cap is on the power connector. I did know that much. I've read through the T.Ms so I know the basics. I have cleaned the contacts with a pencil eraser. It is an LS-454 speaker, so now I know it needs a rewire, but that still does not explain why I get no love from the handsets. The H-250 handset doesn't need any wiring modification does it?

 

[m38inmaine]

No mod needed. Try the LS-454 after you mod it and report back.