Cobra 139xlr 40 chnl SSB no audio, carrier ok

[larbian]

This cobra base has no receive, no modulation, but has a carrier. I was attempting to install an echo board.

\The board is a DELTA EC2 CB ECHO BOARD TURBO

I connected the mic in to the #2 pin of mic jack and the mic out to the disconnected wire from pin 2.

Here's where I made the mistake. Each connection had a ground and a ground for the power feed. I connected the 3 grounds together.
The red power supply I connected to the 13.8v input jack at the rear of the radio and connected all 3 grds to the neg ground on that jack which the antenna ground is connected to that also, so when I keyed the mic it squealed so I figured it was feedback from the common ground so I moved that ground to the negative of a 3300uf electrolytic cap on a separate board from the main board and thats when the audio went out. I should have connected them to pin 1 of the mic jack maybe.
I removed the echo board entirely and replaced the audio wire back to pin 2.
Maybe I shorted that cap out? Maybe I should replace that or at least remove it and test it?

Any suggestions is appreciated.

[MDYoungblood]

My guess is the audio regulator is gone. Recheck your work to make sure no solder joints are shorted.

3's

Greg

[larbian]

Thanks Greg