Humming noise when guitar volume pot is all the way down.

[Rick Lee]

What causes this? Somehow this only happens in the two Strat-style guitars I have with pickguards. Both have 500k volume pots, no tone pots, both have humbuckers. Both sound fine at full and low volume (guitar volume knobs), but both make a loud humming or chirping noise when the volume pots are all the way down. I need to change the strings on one for an upcoming gig, but want to hold off until I know how to address this, which I assume will entail pulling the pickguard off.

 

[Racerxrated]

Maybe spray some Deoxit into the pots and turn them? Might need a cleaning...

 

[311boogieman]

Yes, you will have to take the pick guard off.
Doubt there is anything going on in that cavity that is the issue.
Outside of maybe a solder joint going bad.
Are there any single coil pups in these guitars?
Because there is known 60htz hum in most Strats (with single coils IIRC)
Is this a brand new problem that just popped up all of the sudden?
With both guitars at the same time? If so, what's changed my friend?

 

[Rick Lee]

One guitar has single coils in the middle and neck position. The middle one is not wired up and I rarely use the neck one. I think this problem has always existed, but I don't play these guitars much, so it's been a while since I noticed. I'm going to put a new SD up in the single humbucker one soon. So I'll check everything real closely with that one.

 

[Emg77]

It sounds like the pot to me. Maybe the wiper is warped from over heating the pot or as stated above dirty.Turning it all the way down introduces signal pass.

 

[griff10672]

I'd like to preface my comment by saying I'm not trying to be a dick ....

" time to learn to use a Multimeter .... if you don't already know how "

you'll be able to actually check things .... without guessing .... you'll be able to troubleshoot the whole guitar .....from telling if a pick up has gone bad to something touching something it's not suppose to be .

 

[Rick Lee]

I have a nice Fluke DMM, but don't know how to diagnose a bad pickup, when it sounds perfect at every volume other than with the volume knob all the way down. And if it's putting out with the volume all the way down, is that a bad pot or a bad pickup?

 

[Dan Gleesak]

i agree with Griff above. Get a meter and familiarize yourself with the ohm setting. dollars to donuts it's a grounding issue

 

[griff10672]

I have a nice Fluke DMM, but don't know how to diagnose a bad pickup, when it sounds perfect at every volume other than with the volume knob all the way down. And if it's putting out with the volume all the way down, is that a bad pot or a bad pickup?