I thought I remember reading somewhere that these volume pots can be cleaned?

I get a lot of crackling out of my left speaker in my Back To The Future pin. The second on turn on the machine, I get loud crackle and pops then no sound from the speaker. However, if I turn of the machine, and adjust the volume a bit, when I turn the game back out the speaker works fine.

This may be fine for a several weeks, but then sometimes the crackling popping sound comes back, I readjust the volume pot a bit and all seems to be ok for awhile.

Any ideas? Could the pot be dirty? Loose connection? Or would this have nothing to do with the volume pot at all?

I also just noticed my volume pot has 2 potentiometers in one...is this normal / original? Or could this have been updated at one point....and what purpose is the dual pot?

Do I need to take the pot all the way apart? Or can I just spray a bit into that opening?

Excellent thank you. There is also the cabinet speaker, is this just piggy packing off of one of the pots?

Guys, That DeoxIt worked WONDERS! I only tried the game a few times but so far NO crackling / popping sounds. The volume knob is even much much much more smooth and wayyy easier to turn. I cant believe the difference. And, the left speaker where I was having the issue was also a lower volume then the right but now the volume is the same loudness as the right speaker! Also, there was so much resistance in the knob before, but I'm new to pinball machine so I thought that was normal.

Im blown away...I have been trying to solve this for over a year since I bought the pin. Thought it was the sound board, so I re-capped, thought it was the speaker, so I changed it out, and a few other things I tried.

DeoxIt on the pot was the trick! Thank you everyone!

Jim

I did spray in the shaft as well...pretty much all over as it can't really hurt anything once it dries. Just spray, turn the knob back and forth several times to loosen and dirt / grime / oxidation....then spray again to clean it out.

Wait for it to dry a few minutes and you're good to go!

Jim

Well that didn't end up fixing my problem...the crackling / popping noise in my left speaker came back. However, I believe I have fixed that by replacing a few caps on the sound board. Either way, im sure the volume pot needed a good cleaning anyways. It definitely moves much smoother now.