Pots aren't scratchy - now what's wrong?

[zebra]

I removed the guts of my amp from the cabinet yesterday to clean some scratchy pots using DeoxIT D5 (spray).
Tried my best to do a neat job of it, but that DeoxIt spray is messy stuff - it ended up getting all over.  :doh:

All of the pots work great now - very smooth, and no scratches or pops - but other stuff is not right:

  - The pull-fat and pull-bright switches make are now popping.
  - There's a significant decrease in the volume of the amp (both clean and dirty channels).
  - There's a lot of noise, especially when I turn up the treble.  It's not buzzing, but more like a static from a television non-channel.

:help:

Do you think I fried something, or just knocked something loose when I was accessing the pots?
I'm thinking replacing the push/pull pots wouldn't be a difficult fix, but the volume drop and static noice concerns me.

Maybe the strangest thing is that I was previously getting buzzing from my guitar because it needed to be re-grounded - and now that  noise is gone.  :dontknow:

Thanks for an insight you folks have to offer!

 

[Cagey]

That's a strange mixture of cause/effect/symptoms, which makes it difficult to pick on a cause. Plus, being somewhat invasive, that kind of operation can have more than one effect.

I have little faith in $5 canned miracle cures being effective treatments for failing parts. I've found that "cleaning" sprays don't really clean, they just move contaminants around, and they certainly can't repair something that's worn. Sometimes, if you're lucky, there seems to be a temporarily positive effect, which is what propagates the existence of those "cures". Other times, you just change the symptoms. Bottom line is there are failing parts that need replacement, and that's what needs to be done to get reliable performance back.

If replacing pots doesn't present a problem for you, that's what you should do. Takes a little longer than spraying rapid-evaporating solvents, but the results will last a lot longer and be more reliable.

 

[Rick]

What I've found it that it's either dust or failing parts.  I'd let that miracle stuff dry, and then blow it off with a can of dust off which has no chemicals in it, it's just air.  If the problems persist, you know which pots to replace.

If the amp is more than 20 years old, it's probably time ...

I'm curious what brand is it?

 

[zebra]

What I've found it that it's either dust or failing parts.  I'd let that miracle stuff dry, and then blow it off with a can of dust off which has no chemicals in it, it's just air.  If the problems persist, you know which pots to replace.

If the amp is more than 20 years old, it's probably time ...

I'm curious what brand is it?

It's a Yamaha G100-12.  From somewhere in the early 80s - I believe it's the MkII or Mk III version, going off what what I read on the internet back when I purchased it.  So yeah, well over 20 years old...almost as old as me!

 

[Rick]

Hey, we're in the same club ...

I have a Yamaha JX 30.  I'm the first owner, bought in about 1981.  It has a greaaaaaat reverb tank.

I've replaced the speaker (eminence swamp thing, which I did myself, and the bass pot which someone else did).  I can tell my gain pot is dying, but after I leave it on for a minute or two, and thrash away, it goes back to normal.  So until it's dead, I'm not changing anything.

 

[zebra]

OK, played around with it a bit more - I've determined that the issue is definitely attributable and completely specific to the push-pull pots.  Since there's only 3 of them (and nothing else seems to be wrong), I can get away with just replacing those, and I should be all set. 

Thanks for your feedback!