Quoted from gac:
I have a similar situation. Once in a while, one of the speaker panel speakers (usually the right side and usually occurs when the machine is first turned on) will be much quieter than the other. I find that if I touch the volume potentiometer with my fingers that the sound comes back. There seems to be a bit of static noise but then it comes back.... much like touching a radio antenna when losing the signal. Not sure if its a board issue, grounding issue, potentiometer issue, or what???
You sir are a genius. Of all the things I never tried messing with the volume pot! Tweaking it fixed it and I sprayed some electronics cleaner in there. I’ve been racking my brain!! What an easy fix!