Hum and grounding on my Hamer Studio

[Surfanarchist]

Hi all,

I have a 2008 Hamer Studio that just developed a hum when I take my fingers off the strings. Actually it hums until I touch any metal that is part of the grounded system. If I touch the strings, bridge, cable jack, if I pull the back off and touch the pots, the hum stops. I know what it's doing, using my body to pull the excess electrons out of the system, but I don't know why it just started. I've put on ohm meter to it and everything in the ground circuit is connected, and if I measure from anywhere in the grounded circuit to the end of the connected cable it reads fine so the ground is making it from the output jack back to the amp. Even so I've swapped cables with no change. I know its the guitar since if I plug in my Mirage iI have no issues.

Any thoughts?

[BubbaVO]

Weird. I assume you've already looked inside the control cavity and everything looks good in there. Could the ground wire to the bridge have gotten loose?

[Surfanarchist]

No, the bridge ground is good. Here is a better description, or more detailed, of how the guitar is behaving. If I'm not touching the guitar then it has a slight hum. If i touch a string, the bridge or hold my hand around the cable plug end where it plugs into the guitar then I can silence the hum. If I pluck a string and then let go so I'm not touching any part of the grounded parts of the guitar then it hums BIG Time, until I put a finger on a string and then it stops. Another thing, and this is very strange, if I touch the metal cover to the electronics cavity then I get another big hum. It's the only time touching metal on the guitar makes it hum instead of making it stop. I've put an ohm meter to from the bridge to the pots and from the pots to the cable connector and from all that to the far end of the cable and I've continuity all across. All the solder joints look very good. So there are no breaks in the grounding system. So I'm guessing either a bad component (pot, pup) or should I be thinking about shielding the cavity? Or???

[murkat]

somewhere, an open hot has developed in the wiring, a fraye of wire is just barely arcing to ground. somewhere.

or

you and the guitar have built up a static charge. time to try out the sheets of snuggle....

[BubbaVO]

somewhere, an open hot has developed in the wiring, a fraye of wire is just barely arcing to ground. somewhere.

or

you and the guitar have built up a static charge. time to try out the sheets of snuggle....

I think that murkat is on to it. Your guitar is already shielded - Hamer does a great job with shielding paint in the cavity.

[Surfanarchist]

That makes sense. Hamer uses a shielded wire between the tone pot and the connector jack. The inside wire carries the signal from the 3 way and the shield carries the ground. The shield is soldered to the tone pot with the signal slipping right through. That's where I'll start. After I snuggle myself, the guitar, and anything else I can think of. Here in Kyiv the weather has turned cold ( and dry) so a static build up is certainly possible and something I thought of since this problem just sort of appeared recently. Thanks.

Wayne in Ukraine (can't wait to go home).