Help! P bass noise issue

[Matthew Bryson]

I have a 'new to me' P bass.

I am getting some noise that doesn't seem right. The noise is only present with the tone knob turned up. The p/up is a basslines 1/4 pound if that makes any difference

If I roll off the tone knob a bit, that seems to quiet things down.

With the tone knob up, and the noise present:

If I touch the strings or bridge - the noise does not get quiet (actually seems to get a tiny bit louder)

If I touch the tone knob, volume knob, or input jack - the noise goes away.

Is this somehow normal, or does this indicate a grounding problem?

Any help is greatly appreciated.

[Fontaine]

i think i might get something similar, i just something metal on mine and this little tiny buzzy sound that i can just barley hear when im next tpo the amp goes away =)

[Turnaround]

Sounds like the ground wire from the bridge is disconnected. Since the Pickups are Basslines, I assume they were replacements. Perhaps when they were installed the ground wire became disconnected.

If you are up to it, remove the strings, undo all of the screws on the pickguard and carefully lift off the pickguard complete with the controls - try not to stress any of the wires. There should be a wire coming from a small hole that leads toward the bridge. Make sure it is connected to the back of the tone or volume control. If it is disconnected, solder it on there. If it is soldered, check to make sure the solder joint is sound. Resolder if necessary. Reassemble, restring and try it out.

[seanm]

There is a simple way to test grounding if you have an ohmmeter or a continuity checker. It must be a continuity checker, not a voltmeter, there must be a battery involved.

SInce it looks like the pots are grounded, test the continuity from the tone or volume control to the bridge. It should be a short circuit. If it is open, that is your problem.