Potentiometer Problems

[Life]

So I ordered a Marshal Blues Breaker from GGG. Ended up being about the same price kitted as I could have bought myself so sure, why not.

Wired it up, worked fine installed to start. Next time I booted it though it was dead. Light was on, but no out. So I took it out, thought well maybe a wire is loose. Started playing around with them and found a problem around the 25K Gain pot so I took it apart and reflowed it. Still didn't work so I kept playing around with it and eventually determined the pot to be bad. Jay sent me out a new one and I got around to working on it today. Now the other two pots are bad so I don't know whats going on. I've built about 7 pedals/amps now and never had an issue like this. The connections ARE good but when I move the legs around then pot shorts out. Its not the wires and its not the board, its the pot itself. Has anyone ever had problems like this? The 25K pot Jay sent me works great, no issues what so ever but the other original two exhibit the shorting issue.

I didn't touch the heat on my iron so I don't think thats it.

[Mark Hammer]

These day, just to avoid the sort of heartbreak and frustration you describe, when I get some new pots (almost always the small 16mm Alpha), I ory the tabs, lift the back off, and do two things.  One involves applying a substance that some find hard to get, so I won't go into it.  The other is that I use my needlenose pliers to gently squeeze the rivets holdings the solder lugs.  If the lugs can move even a little bit, then the odds are that they are not making consistent contact with the resistive strip.  The pot may read good when you press your meter probes down on the contacts, but once you remove that pressure, even very tiny gaps can render a pot essentially non-functional.