Fender Concert Amp - Cleaning pots

[The Dude]

I agree that spraying cleaner down the pot shaft is not an ideal situation. That said, sometimes it's the best option. I'm not going to completely disassemble (for instance) a Mackie mixer to clean one potentiometer. Also, for sealed pots without access to the wafer, it's either try getting cleaner down the shaft, or remove the pot from the circuit board, disassemble it, clean it, reassemble it, and reinstall it. I've never created problems forcing cleaner down a pot shaft. The only caveat is that sometimes it's not effective.

[Valvehead]

I wish I would have seen this post 1 day ago.......I have 1 of these nightmares on my bench now. Pulled the boards to clean the pots , re assembled , and now have super low volume. Awesome....coming back apart

[SoulFetish]

I wish I would have seen this post 1 day ago.......I have 1 of these nightmares on my bench now. Pulled the boards to clean the pots , re assembled , and now have super low volume. Awesome....coming back apart

That's the worst. having to pull the chassis after reassembly....
Actually, maybe even worse than that is screwing the chassis back into the cab and getting to the last screw and having the cage nut push into the chassis.

[Mars Amp Repair]

That's the worst. having to pull the chassis after reassembly....
Actually, maybe even worse than that is screwing the chassis back into the cab and getting to the last screw and having the cage nut push into the chassis.

Oh man! And we've all done that!! As as you mentioned, it's always the LAST screw to go in the thing! Why is that? Just ask Murphy

[Mars Amp Repair]

IMO, it's a last resort and certainly not ideal. I've never experienced it causing any lasting problems. I've found that the grease on most pots can reset after some time and drag restored (at least to some degree), but even spraying into the back of the pot can cause this problem.
Drilling an access hole in the PCB is a better solution, but like I said, I would just make an acrylic depth-stop and use a carbide stub drill for safe, consistent results which could probably find use beyond just this model.

FYI,
I drill thru the pcb with the small bit in a pin-vise. That way you have a lot of feedback to know when you're getting close to drilling thru the pbc. Then you just reduce the pressure & place you thumb & index finger around the end of the pin vise in order to stop it from breaking thru & going into the pot. I've never had an issue with this method & was using it back in the 70's on Pioneer receivers where you'd have to disassemble the front panel & go thur all kinds of contortions to get to the pots.
Glen