Volume Pot Crapping Out?

[Uiah]

Hi,
I recently replaced all of the pots in my Les Paul, but now the bridge volume is cutting in and out when i move it kinda like a bad jack that you have to wiggle to get sound other than horrible noise.
Is it possible i damaged the pot with too much heat or more likely a bad solder? Is there a way to test with multimeters?
Any help is much appreciated...

[Chuck H]

The multi meter will only tell you if it's working or not. And there's no way for the multi meter measurements themselves to tell you if the solder joints are bad or if the track swedges or wiper contacts have been compromised. Further, if the problem is intermittent you may not be able to detect a fault at all with a multi meter.

I have damaged pots with too much time/heat from soldering. It happens. Pot lugs with two leads on them or a bare wire to a solder blob on the pot back sink a lot of heat. And sometimes solder can be stubborn. Too much time with the iron tip on a lug can deliver too much heat to the rest of the pots construction before the solder melts. I've seen this cause bad contact on the lug to track swedges on pots. Admittedly this was early on for me when I did not have a proper soldering station with a well tinned tip.

"I" would reflow the solder contacts with fresh flux and replace the pot if that doesn't help.

[Mick Bailey]

What brand and type of pot are you using?

[Uiah]

The multi meter will only tell you if it's working or not. And there's no way for the multi meter measurements themselves to tell you if the solder joints are bad or if the track swedges or wiper contacts have been compromised. Further, if the problem is intermittent you may not be able to detect a fault at all with a multi meter.

I have damaged pots with too much time/heat from soldering. It happens. Pot lugs with two leads on them or a bare wire to a solder blob on the pot back sink a lot of heat. And sometimes solder can be stubborn. Too much time with the iron tip on a lug can deliver too much heat to the rest of the pots construction before the solder melts. I've seen this cause bad contact on the lug to track swedges on pots. Admittedly this was early on for me when I did not have a proper soldering station with a well tinned tip.

"I" would reflow the solder contacts with fresh flux and replace the pot if that doesn't help.

Great thanks mate, will do.

[Uiah]

What brand and type of pot are you using?

CTS

[Mick Bailey]

CTS pots are perhaps the most tolerant of excessive heat to the solder lugs, but some types - the ones where the nylon wiper carrier bears against the inside of the shell - can be damaged by excessive heat when soldering to the shell. Apart from this, I've had quite a few brand new CTS pots that have been noisy or intermittent from new and required cleaning. Another thing to watch if you use the long shaft type is that they no longer have a clip fitted to prevent the shaft being pushed towards the shell. When you come to fit the knobs even the slightest force will open up the crimps and the ones that give the most are the ones that hold the threaded bush. The whole thing becomes loose and can result in poor contact between wiper and track.

Oh, stating the obvious - make sure you don't have a solder bead that;s rolled inside the pot.

[Uiah]

CTS pots are perhaps the most tolerant of excessive heat to the solder lugs, but some types - the ones where the nylon wiper carrier bears against the inside of the shell - can be damaged by excessive heat when soldering to the shell. Apart from this, I've had quite a few brand new CTS pots that have been noisy or intermittent from new and required cleaning. Another thing to watch if you use the long shaft type is that they no longer have a clip fitted to prevent the shaft being pushed towards the shell. When you come to fit the knobs even the slightest force will open up the crimps and the ones that give the most are the ones that hold the threaded bush. The whole thing becomes loose and can result in poor contact between wiper and track.

Oh, stating the obvious - make sure you don't have a solder bead that;s rolled inside the pot.

Thanks Mick, that all makes sense. Is there a way to push the knobs back on without opening up the crimps?

[Mick Bailey]

You have to press press on the back of the shell while you push home the knob. I sit with the guitar sideways across my lap, put my thumb against the shell and use the other hand to locate the pot and press it on, balancing the force to prevent the shell being pushed backwards. You can tell if the crimp has opened up because the shell will move at either end of rotation. The design flaw is very similar to Mesa amp controls where pressure on the knob pushes off the shell and results in poor contact.