Uggg Ground hum

[TBurst Std]

My Strat was previously noiseless. I desoldered the jack and trem claw wires and installed the pups, pots and switch into a new pickguard. Decided against it and put it back into the original pickguard. No pup, pot or switch wiring was touched.

I now have a slight ground hum (measured in positions 2 & 4) that goes away when you touch the strings. I have compared this against my other guitars that do not have this issue, so we can exclude lights, power, dimmers etc.

My 1st thought was a bad ground to the trem claw. I undid that joint and made a mechanical joint that I could test. Unjointed, the hum was worse, and touching the strings made no change. Guess its not the joint at the claw (which is now restored).

Next thought was the jack. Though the hum isn't of the intensity of a reversed ground, I wanted to validate. I desoldered the jack and made mechanical joints. Wired as it was, I had the same slight ground hum as before.  Reversed the hum was more, and when strings were touched, it worsened.

So I have ruled out the jack and claw joints, the only ones that were touched. On inspecting the untouched ground joints, they all appear good.

Your thoughts, where do I look next to have this back to its original condition?

 

[TonyFlyingSquirrel]

Check the 5 way switch for any potential short circuits in positions 2 & 4.

You may have some terminals touching each other.

 

[TBurst Std]

Many thanks TFS. The ground hum occurs in all positions, I just used positions 2 & 4 as they are humbucking (so a more valid test). I'll take a look at terminals as well as pot lugs tonight. Maybe something got bent during the transplant and back.

 

[TBurst Std]

Well all terminals and lugs look ok. Will post some pics.

 

[TBurst Std]

Neck pup

 

[TBurst Std]

Mid pup

 

[TBurst Std]

Bridge pup pic wont post

 

[TBurst Std]

vol pot

 

[TBurst Std]

tone pot

 

[TBurst Std]

blender pot

 

[TBurst Std]

switch

 

[TBurst Std]

Anything look astray? No pup, pot or switch joints were touched.

 

[TBurst Std]

Bridge pup

 

[Logrinn]

Where is the trem claw cable connected?

 

[stratamania]

Another thing to check are the wires you did solder and unsolder. Perhaps the one to the claw for example could benefit from being replaced.

 

[TBurst Std]

Where is the trem claw cable connected?

to the trem claw. I originally had it soldered, no issues. Upon the transplant, I soldered it again. That is when the hum occurred. To test it, I desoldered it and affixed a lug for a mechanical connection. In testing it, slight hum not touching strings. No hum when touching them. When disconnected, more hum not touching strings, no change when touching them.

 

[TBurst Std]

Another thing to check are the wires you did solder and unsolder. Perhaps the one to the claw for example could benefit from being replaced.

I will take another look at them, but upon my previous inspections, they appear fine. Will check continuity.

 

[Logrinn]

Where is the trem claw cable connected?

to the trem claw.

No, I meant, where on the pickup/pot/pickguard is it connected? I couldn't see it on the pictures.
Is it soldered to the back of the volume pot?

 

[TBurst Std]

It is soldered to the left lug (most CCW from the top) of vol pot.  Have not moved that joint.  Upon inspection, the joint appears good, but also that structurally is suspect to being the weakest joint.

 

[Logrinn]

Ah, ok, I see it.

One thing I'm thinking about ... You said in the original post that you now, after swapping and reswapping the pickguard, have a slight hum that disappears when you touch the bridge. I believe this to be quite normal.
But it also implies that you didn't have any hum when not touching the bridge before, i.e. when you didn't ground the guitar. I have experienced this a few times, but it's more uncommon.

If there's no hum when you hold and play the guitar, then it's like most guitars out there.