Hey there! I've never posted on the strat forum but I have a question specific to a strat style guitar.

To make a long story short I bought a guitar for 25 bucks, painted it green and cleaned it up. Me and my dad put it back together and I get this awful loud humming noise from my amp.

So here is why I think it is todo with grounding: the buzzing begins when I touch any metal on the guitar (the strings, the bridge, etc....) but it disappears when I either touch the input jack or a piece of metal on the amp. Leaving me to belive there is a problem with the grounding on the input jack or something.

I can add more detail if needed but has any one ever had a problem like this? If so what can be done and how can I do it with out taking my guitar completly apart. See the guitar has an over hanging fretboard for a 22nd fret. And if I remove the pickguard the neck has to come off as well (what a hassle.)

So any help will be GREATLY appreciated! And I can post some pics if need be.

Thanks to any one with help,

Will P

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

Do a "search" on the topic 'shielding your guitar'.

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Being able to play and enjoy music is a gift that's often taken for granted.

Don't leave home without it!

So you believe it is to do with me shielding it? I'm not sure if such a thing would be an easy fix, as I'd have to order stuff online to do it?

Thanks for the reply, I've heard of shielding. But I don think this is just typical single coil hum. I think it is a full out grounding problem.

Of course I'm no expert I'll look up the shielding thing.

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

Also I should add that if you turn the tone nob all the way down the humming stops, but alas I have no tone.... Also the humming gets louder and louder the more I turn the volume nob on the guitar DOWN so I always play it with the guitars volume at max.

It's probably a really stupid common problem, guess I'll just have to fidle around with the innards and see if I can fix it my self o_o

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

Did you run a wire from the common grounding point to the back spring cavity, soldered to the claw? Looks like you are missing that. hat wire will ground the bridge, trem and strings.

Does indeed sound like an incomplete or incorrect ground.

Your body is a great collector of noise, so when you touch ungrounded metal in the guitar, you are adding your noise to the output signal. But when you are grounded (like through the metal on the amp or the input (output?) jack plate) and holding the guitar near your body, you make a great shield - alll the noise you collect goes to ground instead of into the guitar and so into the amp hot. To see what I mean - touch just the very tip of the amp cord where it usually plugs into the guitar and the amp output will be very noisy, but ground yourself and it won't be(though you may hear a hum due to the path through you between ground & the amp hot.

So - by touching different metal objects on your guitar while holding it, or better yet getting a continuity checker/meter and checking vs definite grounded metal like the jack plate or amp metal, it seems you would be able to test what components are correctly grounded and what aren't.

All metal components including the bridge (and so the strings and tuners), the pots, the PUPS, the switch, etc. should have a connection to ground, and usually the body cavity is grounded too. Just make sure you don't create ground loops.

Yes well there is a wire soldered in the back just like you said but I guess it's not doing it's job right? Perhaps the wire is faulty or just broken? Or is it possible I didn't use the correct type of solder to atach it as I've there are diferent grades of it.

I could also replace the grounding wire if it is broken? What type of wire would I use to do so?

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

Thanks a ton!! That helps a whole lot! Now if did find out what parts were incorrectly grounded how would I fix that part? I guess that's what I need to know. HOW do I fix it?

Thank you very very much for the reply!

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

There are wiring diagrams on this site under Support/Technical Specs, they show the ground wires as thin lines connecting the solder globs on the rear of the pots, going to the Trem Claw, the output jack, etc.. They are called out as "black wire from output jack", "18", and "to trem claw for grounding" in this pdf.

White wires are hot signals from the PUPs, and eventually go to the + lug on the output jack.

Make sure you go to the right lugs with your wires - you may be shorting hot/output signal(s) to ground!

http://support.fender.com/diagrams/stra ... 22APg2.pdf


It might help to think of the PUPS as little AC generators (which they are) like batteries - the +/white/hot wires eventually go, through the selector switch, to the + lug on the output jack - where they pass into the amp + and become your sound. The -/black/grounds gather together and, along with ground wires from the bridge, body, and pots, (and all the noise they collect) go the ground lug on the output jack where they pass on to the amp ground & eventually into the wall.

Volume & tone pots work by dumping some of the output/hot signal, through their variable resistance and any tone capacitors, to ground also - that is why 1 of their lugs is also connected to ground at the rear of the pot.


Oh, and re: wire...

A light gauge wire like a 20ga THHN is fine, 20ga is plenty as we are talking milli-amps, 22ga works well too. You will need a 15/30W soldering iron, solder, wire strippers. Pretty basic stuff!

Thank you so much! That is very helpful! I think that should be enough to fix it,

One last question..... On the diagram the "18" I'm guessing is were you ground the electronics to the body cavity am I correct? My guitar doesen't have that so what can I do about it? Should I add one and what would I do for it? Would any piece of metal screwed in work?

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

I am not sure but I think there is some sort of shielding paint used on strats. By using this lug, which is just screwed to the body with a wood screw, the entire body gets grounded - pretty cool for shielding!

I think if you ran a wire with a ring lug on the end from a convenient ground point (rear of a pot or output jack grnd) and screwed it in to the wood in the cavity (or, instead of a ring lug, just strip the end a little long and wrap bare conductor around the shank of the screw)- you would be as good as you could get.

Man thanks alot! This has helped a lot. I'll post later on if it all worked or not, glad some one knew what might be wrong!

Will P

_________________
Basses:
Fender '51 P bass RI
Squier affinity jazz bass
Guitars:
Squier tele custom
Amps:
Peavey Max 115
fender rumble 15

Last words of advice...

take your time!!
think about what you are doing, and why - ask "why is it like that?"...all things considered it should be pretty straight forward to figure out what's what.

BE CAREFUL of the soldering iron and solder - easy way to ruin a nice finish!

Don't overheat a pot - can ruin the insides (often tough to melt those big globs on the back of one)

Use cardboard to protect the body wherever needed.

don't mix grounds and hots! be sure to check which is which on the output jack.

Oh - and soldering irons can generate EMI/RFI noise - consider that when trying out your project.


Have fun and good luck!