I have a PRS Tremonti and it has started humming suddenly. But the thing is, the hum stops when i touch anything metallic (switch, bridge, string), which leads me to think that the grounding is broken somehow. Now, I've not opened the wiring cavity to check yet but before I do something stupid and break the thing, can anyone tell me how I can identify the ground wire and where should i re-solder it to?

The hum is supposed to go away or be reduced when you touch metal parts that are grounded. Does the hum go away (or reduce) when you touch the strings? If not, then the string ground has become disconnected or intermittent, probably at the bridge and not at the control cavity. How to go about fixing it would depend on what type of bridge or tailpiece you have.
Last edited by Invader Jim at Jul 15, 2014,