"Jeff Urban" wrote in message
...

If there's no noise between stations with the muting off it's probably
oscillating. That would maybe indicate filters or bypass caps. If the
frequency actually drifts, assuming it has ONE fault which is usual,
look around the FM oscillator or mixer stages.

What about a dead LO or mixer?

If you have a 100MHz 'scope, you should be able to trace through the front
end and IF.