I have a Cobra 148GTL AM/SSB citizen's band radio that appears to be
fairly old (made in Taiwan) and has the following problems:

(1) Despite what LED channel indicator shows, the receiver doesn't
change frequency.

(2) When I push the mic push-to-talk button, no signal is transmitted
and the receive/transmit (RX/TX) light remains green (receive mode).

(3) When I first got the rig, it did transmit and change receive
channels, but on frequencies above the CB band.

I suspect the problem is in the frequency synthesis phase-locked loop
or related circuitry. Did a capacitor failed after being uncharged for
years?

I thought I'd ask newsgroup readers for any insight before I charge in
with my oscilloscope and soldering iron. Perhaps some of you
encountered similar problems with this unit and can suggest a good
starting point diagnosis and repair.

-Dave