ilovefuzz.com

I don't know if this is the right place to ask this, but I imagine you folks will know more about this than I.

I had an LED fixed in an overdrive of mine; when it came back, I'd swear it hums more than when I sent it out. Way worse with P-90s (on all pickup configurations), and when I use the middle-position on my Gretsch, it disappears altogether.

I poked around the insides with a small screwdriver. When the screwdriver came into contact with the first of three lugs on the volume pot (looking at it from the back) and I touched my strings with my other hand, the hum changed - less "buzz," and decreased down to what I thought was a "normal" gain-related hum. Same thing happened when I used the screwdriver to contact the solder joints of a red cap (I think the volume pot is directly wired to this).

Is this symptomatic of a joint that needs reflowing somewhere in the circuit?

Sounds like a grounding issue to me. Generally, if you touching the strings (or any metal bits on the guitar, like the jack plate) and the noise/hum goes away or gets way quieter, it's got something to do with grounding.

What pedal is it? Maybe post some gut shots and we can have a look-see.