Pup cover "buzzes" when touched... where should I look to fix it?

Stratfan

New member
I'm getting ready to clean and re-string a friend's SG copy. (He's a bassist, and evidently never heard of replacing old strings!) I noticed that the bridge humbucker "buzzes" when I touch it. I'm guessing that it's a ground problem. I've never gone into any guitar but my Strat, so a few helpful hints on what to look for would be greatly appreciated! I assume that the first thing would be to look for any unconnected wires. Thanks.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

Well, I opened the control cavity and couldn't see any loose solder joints. The logical next step would be to plug it in and wiggle wires until I find something. I hope that the problem is in the control cavity... I don't want to pull out the pup and pup ring since I've never done it before (and it's not my guitar).


BTW, the buzzing (humming?) is only when you touch the bridge pup cover; the neck pup is fine.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

So far I've discovered (while touching the bridge pup cover):

1. If I turn down the bridge tone control the buzzing goes away.

2. The bare wire (braid?) from the bridge pup lead is soldered to the base of the volume pot. When I wiggle this wire with a pencil, there is no change; I guess the solder joint is okay. When I grab it with my fingers the buzzing stops.

3. The intensity of the buzzing changes when I gently tug on the bridge lead coming out of the hole in the body.

4. The bridge pup has a little play in it, and if I wiggle it and give a little push in the right direction the buzzing stops.

I'm a complete amateur when it comes to guitar wiring, but my guess would be that there's a short in the bare ground wire somewhere just below the pup, or in the pup itself.
 
Grounding problem???

Grounding problem???

Need Help!!!

While cleaning the guitar body, I unscrewed both pup rings and lifted them up a bit to clean under them. After re-stringing, I plugged it in to tune up, and now the bridge pup is okay. But, the neck pup "crackles" when I touch it. Also, when I play using the neck pup the crackling noise comes through the amp even if I'm not touching the pup. I touched the guitar cable's jack at the input and the crackling stopped. I'm thinking some kind of grounding problem; hopefully in the control cavity.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

After wiggling the neck pup a few times the crackling is gone. I know that it's not "fixed" gone... but rather now it's intermittent. Unless anyone has any tips, I guess that this guitar will need to be taken in to the shop.

On the plus side, the guitar is nice and shiny, and with a new set of DR strings it doesn't sound too bad for a cheap copy!
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

More info:

Today I plugged the guitar in along with dirt pedals. (I figured that with added noise from pedals it would be easier to hear changes in the humming noise.) With distortion, there is a slight hum when using either pup which disappears when I touch the input or either pup cover; leaving only the pedal noise. No matter which pup the switch is set for, the hum decreases when I turn down the tone knob, and sharply increases when I lower the volume knob! Touching the cable's jack plugged into the guitar kills the hum, and so will touching either pup cover no matter which pup is selected.

This has got to be a simple grounding problem, but I need help knowing which connections to check... that's why I've posted everything that is happening.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

bad jack...simple things first. It probably could use a better one (namely Switchcraft) anyway.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

Thanks! I guess that to check the jack I'd have to unsolder the 2 wires to remove the jack from the circuit and test it with an ohmeter, right? If that's the case, I should just replace the jack anyway. I know it's not my guitar, but I do use it occasionally so I might as well try to fix it!
 
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Re: Pup cover "buzzes" when touched... where should I look to fix it?

From what you've described so far, you seem to know electric circuitry quite a bit. Yes, it sounds like the problem is around the jack area. I would check if the spring that pushes against the ring is tight and I would also check the instrument cable for continuity. One thing that most people may not notice is that on some cheap cables, there may be oxides on the ring of the plug which causes intermittent disconnects. Make sure that the ring is clean also. I would check for continuity on all parts before I close up everything. Good luck.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

Amateur, I know just enough to get me in trouble!

All guitar cables are good; I have no problems when I plug in my Strat.

I sure hope it's the jack... I hate soldering wires to the back of a pot!

(Note to self: Never, ever, post a pic of the sloppy job I did when changing Strat pups.)
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

When hum gets louder when you touch metal, the leads are reversed (usually at the jack).

Check all solder joints for continuity with a multi-meter. Can't tell if a joint is sound by sight alone. If the problems are still there connect each component, one at a time, directly to the jack.

The one that hums is the culprit.


Also, this is what I do for soldering to the back of a pot, but I think it pretty much applies to guitar soldering in general (except maybe for the widest tip part):

-use the widest tip you have for the back of the pot
-let iron (40-45 watts) heat up. when solder flows onto it, its ready to go.
-tin (tinning is applying a thin layer of solder to every surface to be soldered) tip before using it for the first time and keep it wet throughout process. dry tip wont work
-scuff up back of pot
-put flux on pot
-tin back of pot
-put flux on wire
-tin wire
-put flux on pot and wire again
-put solder on tip until a tear drop forms (doing it this way prevents the need for a 3rd hand!)
-put wire on pot
-put tip on wire and pot
-solder will flow onto both
-remove tip but hold wire on pot for a sec or two
-unplug soldering iron
-your done

*NEVER use a soldering gun, only a soldering iron. If in the process of tinning the back of the pot you leave too much solder behind, remove the excess with copper solder braid.

Also make sure not to check for hum until the guitar is completely strung up. I've gotton all sorts of noises with just a low E, but dead quiet with all six.

Weird, but it happens.
 
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Re: Pup cover "buzzes" when touched... where should I look to fix it?

I think I'll disconnect the jack and check it out first...

If the jack is bad, hopefully the local music store will have some. I need to get new knobs for this guitar anyway; I broke one while trying to remove it when I cleaned the guitar! These stock knobs are cheap, flimsy, and brittle.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

Disconnected the jack and tested it; the jack's okay. I did bend the pressure plate (or whatever it's called) a bit so that the cable isn't so loose when plugged into the jack. I re-soldered the wires to the jack (and re-soldered one of the wires going to the bridge volume pot which didn't feel like it had a strong connection) and then plugged in the guitar. Finally, some good news: the constant humming/crackling noise is gone. But, the neck pup still buzzes when I touch it, and the buzzing lowers in volume when I also touch the guitar cable in the jack. The problem could be anything; a bad wire, bad pot(s), or probably a bad pick-up. Luckily, the guitar is now in a more playable condition.

The fact that it isn't as bad as it was before makes me feel like I actually accomplished something! It was fairly hard to solder because the pots and their lugs/terminals are so tiny! I'm not used to this; at least the pots in my Strat are larger. For an SG copy (the brand name is Regal) this guitar plays pretty nice. I'll tell my friend that his best bet is to eventually have all the electronics replaced with quality parts, and then he'll have a sweet little beater guitar. But, the fact that it was so dirty and the strings were never changed leads me to believe that he'll end up keeping this guitar as is.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

I'd not asked this before. Is the neck pickup a humbucker or P90 type? A P90 type of pickup will buzz if there is noise in the system. If it is a humbucker, you can try hooking up a jumper wire from the mounting plate to the spot where the ground wire connects to the pot and see if it quiets down. If that works, you know you have a bad ground wire. You can solder the jumper wire and take care of it. You may try this even if the pickup is a P90 type and see if that helps.
 
Re: Pup cover "buzzes" when touched... where should I look to fix it?

Thanks, Amateur! (BTW, the pups are humbuckers.)

I'm guessing that by "mounting plate" you mean the bottom of the pup? As for the pot, which one? Are you talking about the ground wire coming from the pup?

Well, ground is ground, so as long as I jumper the pup to a ground I should know more.
 
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