Stereo operation question

[p911dad]

I have question for our stereo buffs: My now old Yamaha DSP A1 amp is working strangely. Some of the speakers stopped working. I checked all the cables, switched the speakers around, checked the inputs, sprayed Deoxit into the balance switch, checked the fuses and relays (sprayed them too) and nothing changed. I am trying to avoid taking it in to a shop as it is heavy, 60 pounds) Then this morning i turned it on, still nothing. I cranked it up half way (that is a LOT on this thing) and suddenly all the speakers came back, and they work on any volume setting. Any ideas why this could happen? Thanks

[stevej37]

Could it be as simple as the volume/potentiometer is needing replacement?
Work that knob back and forth a dozen times or so.

I am no expert..just an idea.

[MysticLlama]

My Marantz receiver has a muting option that doesn't completely shut off the sound, maybe something like that it getting stuck on somehow?

[greglepore]

There are probably output relays that protect the output transistors. Sometimes they stick...

[Superman]

If the flux capacitors are old, then they should be replaced.

[p911dad]

Thanks guys, I have some 100% Deoxit coming, I will take the cover off again a give all the usual suspects a bath. I changed out the flux capacitors last year, hard to find these days with the chip shortages.. I found the mute control, it is off. Thanks