Please help! Gibson Les Paul up...ground hum :(

[JSatch69]

Hi.

So after a whole day of messing around with my Les Paul. It still isn't fixed.

I removed all remnants from the old braided wiring and wire the pickups directly.

I wired a ground running across all the pickups.

I tested everything and thought this should work now.

It didn't. I got massive loud hum and it was huge when touching the toggle.

I got frustrated.

So then I thought I'm using the Seymour Duncan wiring diagram but the guitar isn't wired that way. So I then began to recreate the SD diagram. SO I had to resolder the lugs away from the pots. Change the caps wiring.

It was going well. I was nearing completion as I was about to solder the last bridge Volume pot to the pickup hot and onto the BRIDGE tone pot.

I was testing continuity and I noticed the Bridge Vol Pots HOT connection was linked to ground. It shouldnt be! The lug was grounded when it had no physical reason to be.

I thought I was screwed.

Then I thought let me unsolder the other outer lug out and see if I could use that as my hot. I read it will reverse the effect when turned. So I did that and it was clear from the ground.
I just want a working guitar so I would have let it go.

Again, I was finished.

Went to test it. It was godawful.

I then found that the centre lug of the Bridge Vol pot was connected to ground.

The Bridge vol pot lugs are grounded and I have no idea why. Basically its unusable.

I thought I'd try the neck pup only and that sounds terrible.

Basically in the process of switching out my pickups, I've messed up my new Les Paul.

 

[Exluthier]

Okay first off post pictures of how the electronics look right now. Good pictures so that we can see what's going on then we'll go from there.

 

[JSatch69]

Here it is...in all its glory. I used a lot of electrical tape to shield wire and improvised in some areas. Look at the bridge vol pot.

Thanks

 

[the bull]

What are all those wires running to the output jack?

 

[JSatch69]

What are all those wires running to the output jack?

Middle lug from toggle to jack. It looks like 2 wires but its 1 in black/red color.

 

[your idol]

is the jack nice and tight. i used to have a nasty buzz in my sonex out of nowhere and i bent the prong in a bit on the jack and the hum went bye bye. it seems small but you have to check everything when it comes to electrical gremlins...theyre annoying and can even be painful

 

[the bull]

What is the skinny blk wire runnining to that plate from the pickup side?
Is the output jack ground okay?
Why are you not grounding it to a pot?

 

[Exluthier]

There's a ground plate in the cavity that that small board is attached to. The jack is supposed to get grounded to that. Why is the wrong lug soldered to the bridge volume pot?

Did you run a new bridge ground wire? I don't think I've ever seen one with that much slack to it.

 

[the bull]

If you are going to use the plate then run your jack wires like I did.....

 

[JSatch69]

There's a ground plate in the cavity that that small board is attached to. The jack is supposed to get grounded to that. Why is the wrong lug soldered to the bridge volume pot?

Did you run a new bridge ground wire? I don't think I've ever seen one with that much slack to it.

That was a stock ground wire. Lot of slack indeed

I changed the lug on the bridge vol pot as the other is mysteriosly connected to ground same with the centre lug .

I've ordered new components

 

[Exluthier]

Shouldn't have done that, unless you fried a pot this is still salvageable. Did you make sure that the bridge ground is still connected? The middle lug on the vol pot should have either connected to the switch or the lead from the pickup depending on what style of wiring was used, I don't remember off hand. Are you saying it was soldered to the pot?

 

[06VM]

This is alittle off topic but it just reminded me of something:

My guitar and amp is dead quiet at my apt, no buzz or humm. But when I lug them over to my buddies place (40's era house) the guitar adopts the worst ground hum I've ever heard. Of course it goes away when I touch the strings.

When my friend first moved in there he though it was his guitar humming due to damage sustained during the move. had all the pick ups , pots, caps all replaced, had his ac30 retubed and serviced. Hundereds of dollars later it all still buzzed like mad.

Ends up his house had bad wiring and was poorly grounded.

 

[Exluthier]

I think he mentioned in another post that he has another guitar that's quiet through the same rig.

 

[RNBQ]

Nothing more frustrating than trying to run down an electrical problem in a guitar...!

1. If it were mine & since you've already gone about changing things out, I'd forego the shielding plate...remove it, & rewire the whole guitar 50's/Modern style (whichever your prefer) w/ braided wire & all new pots/caps since you prolly might have already heated them up beyond belief? Also: get some heat shrink tubing to tie off the Duncan conductor wires that aren't going to be used...instead of using electrical tape.

A wire-up can look very simplified this way & be hum-free:

50's style being my choice:

2. If you don't want to remove the grounding/shielding plate: Here's some pics I've saved of LP's wired-up w/ the plate that might help you get back on track?

 

[JSatch69]

Shouldn't have done that, unless you fried a pot this is still salvageable. Did you make sure that the bridge ground is still connected? The middle lug on the vol pot should have either connected to the switch or the lead from the pickup depending on what style of wiring was used, I don't remember off hand. Are you saying it was soldered to the pot?

Ok. Bridge ground. Is connected. I do continuity tests between that wire and the metal on the bridge. It beeps. Same with other metal parts on the guitar.

The middle lug should go to the switch.

I'm using the SDuncan method.

The Bridge Vol pot:
I had to unsolder the Left lug which was soldered to the pot as ground and use that as my hot. But when I separated it from the pot, i tested the connection with my multimeter and noticed it that it was connected ground.
Somehow. I thought maybe some stray solder or wire was touching it but I checked and I just couldn't explain it.

So I thought I'd try the Right lug. But then I noticed that the centre lug leading to switch was grounded too when it shouldn't be.
The whole pot is just not right.

I got so frustrated I just ordered new components.

 

[JSatch69]

This is alittle off topic but it just reminded me of something:

My guitar and amp is dead quiet at my apt, no buzz or humm. But when I lug them over to my buddies place (40's era house) the guitar adopts the worst ground hum I've ever heard. Of course it goes away when I touch the strings.

When my friend first moved in there he though it was his guitar humming due to damage sustained during the move. had all the pick ups , pots, caps all replaced, had his ac30 retubed and serviced. Hundereds of dollars later it all still buzzed like mad.

Ends up his house had bad wiring and was poorly grounded.

Its not my house. I'm certain.

 

[JSatch69]

Nothing more frustrating than trying to run down an electrical problem in a guitar...!

1. If it were mine & since you've already gone about changing things out, I'd forego the shielding plate...remove it, & rewire the whole guitar 50's/Modern style (whichever your prefer) w/ braided wire & all new pots/caps since you prolly might have already heated them up beyond belief? Also: get some heat shrink tubing to tie off the Duncan conductor wires that aren't going to be used...instead of using electrical tape.

A wire-up can look very simplified this way & be hum-free:

50's style being my choice:

2. If you don't want to remove the grounding/shielding plate: Here's some pics I've saved of LP's wired-up w/ the plate that might help you get back on track?

Does using the plate have any benefit???

And what is that lovely wire you're using for grounding the pots together. It looks like guitar string???

 

[RNBQ]

Does using the plate have any benefit???

And what is that lovely wire you're using for grounding the pots together. It looks like guitar string???

Not sure why the plate is installed (grd zero?). I like the simplicity w/o it. LP's never needed it back then, so I see no need for it now! It you do yank it, you'll need to check what Pot Shaft length you will need...in case you want to install new Pots?

That's called Buss Wire. It completes the ground, since there is no plate. Prolly a Radio Shack item. I got some from a local tech shop.

This a shot of how LC from CV Guitars wires-up his Faded Stds (50s style). He must of run out of CTS pots that he normally uses on the LCPG's, so he supplied NOS CGC Gibson pots on mine instead?

 

[mightymike]

@OP: Are you sure sure that this hum occurs just because of the pickup swap? Personally I'd say I smell a grounding problem with the amp/the in-house electricity (like it has been mentioned a few comments above). I have exactly the same problem from time to time with my guitars: as soon as I touch the metal parts of the axe the hum is gone.

Of course that's just speculation, but please, before it's driving you mad double check that there are no other factors producing that dreadful hum! Not that you slaughter your innocent guitar in vain!

 

[L.Campionero]

Pardon my ignornce, but the pott in the bottom of the photo doesnt appear to be grounded any where. Is it grounded throgh the metal plate?