Grounding/buzzing problem

[chille51]

Hi all. Just completed my first crack at wiring up a guitar, and all of my switches and pots are doing as they are supposed to. Unfortunately, I've also got a serious grounding issue it seems. The guitar buzzes like crazy on both pickups. If I touch the metal surround on my patch cable, it dulls the buzz considerably. Touching the strings or any of the metal parts on the guitar doesn't change anything... only the patch cord.

I opened it back up to check for cold solders etc., but everything seems to be attached pretty tightly. I unsoldered the bridge ground wire to redo it, and in the process happened to touch it to the first pin on the tone control. The buzz went away then, when touching this pin, which in turn is connected to the first pin on the volume pot. This only works when the volume pot is on full. As soon as I lower it, the buzz comes back. These details probably don't matter, since obviously I DON'T want to connect my ground here anyway... but just trying to give as many specifics as I can.

So.... any advice on where to start to chase this problem down and fix it? This is a LP style guitar, 2 hb, 2 volume, 2 tone, 3 way, master coil split on push pull, phase switch on push pull.

Thanks!

[newey]

Chille51-

My first, off-the-top-of-my-head thought was that you might have switched the wires at the output jack. That would be an obvious first thing to check, anyway.

Beyond that, more involved troubleshooting will be needed. Do you have a multimeter?

[chille51]

Thanks Newey. I've verified that the output jack is wired correctly, and I didn't actually change anything there. I'll verify that I didn't reverse the other end of the lead, that comes from the output jack though. And yes, I can get a multimeter. Would I just start at one end of the circuit, and start testing for continuity?

[newey]

Would I just start at one end of the circuit, and start testing for continuity?

No, if the guitar is working (except for the noise), then clearly the circuitry is continuous.

It sounds like a grounding problem, as you have surmised. What you want to check for is a good ground to all components and to the bridge/strings. Connect a guitar cable to the guitar and clip (or touch) one lead of your meter to the barrel of the cable. Start with the strings and work your way inward. You should get a reading of no more than a couple of Ohms if a point is grounded properly. Check the bridge/strings, the backs of each of the pots, and anywhere else there's a ground connection.

I unsoldered the bridge ground wire to redo it, and in the process happened to touch it to the first pin on the tone control. The buzz went away then, when touching this pin, which in turn is connected to the first pin on the volume pot. This only works when the volume pot is on full. As soon as I lower it, the buzz comes back. These details probably don't matter, since obviously I DON'T want to connect my ground here anyway... but just trying to give as many specifics as I can.

This statement is what led me to suspect that the jack was reversed. You should have continuity between the toggle switch center connection and the tip of a guitar cable plugged into the jack. If you don't, it's miswired.