bbrocks

The guitar's wiring may "look" fine on a quick visual inspection, but you'll need to have another look. Somewhere in there, you've got what "should" be a ground wire that's not actually making it to ground.

Last time this happened on my guitar, it was from my shielding material-- while I was very careful to make the whole thing continuous, I somehow forgot to solder an extra wire going from the shield to ground. That's just one example-- in any event, something's not making it to ground. Trace the route-- wherever the loop is, it's connected to your bridge, which is touching your strings. So follow the lead from the bridge to wherever it goes... does THAT spot lead to ground? If not, you have a loop.

Even with all the wires seeming in place, my understanding is that they won't always go to ground. If the path of least resistance isn't ground, it'll also create a loop. The best solution to avoid this is to ground everything with a "star grounding" scheme. This means taking every single ground, connected them up to one place (the "star" is often just a metal washer), and then from the "star" to the ground lug of your output jack.

Greg

Thanks for the advice, I took it and followed your direction and it led me tot he pickup covers. The owner had replaced the pickup covers with cheap gold looking covers. Apparently something in the gold foil was shorting out the circuit. I removed the covers and the buzz was gone. Now I notice that the bottom tone control isn't quite working so I will continue to check that out.

I have a 50s reissue strat from about 1996. When a live pickup in touched it produces a static hum. When not touched the guitar is quiet. I've visually checked the wiring and everything looks fine. I know this doesn't mean much. I am looking for some pointers on where I should start my troubleshooting.

... When the vol. control was closed got a 0.00 reading on the 20ohm part of the meter. I gradually turned the volume up and got about a third of the way on it's sweep and had a 19.51 reading. As I went on the reading went to 0.L until I got the the last third of the sweep and then it read 18.1 and continued to decrease to 7.13 at the top end where it stabilized. I tried the tone control but the reading did not change.

okay, this is all normal so far.

you probably mean 20K ohms on the meter setting, right?

- when the volume was at zero, you are reading the wiper being right up against the CCW end of the pot - no resistance -- good.

- as you approach the point where the resistance is equal between the wiper and each end of the pot (about 8 on the knob) you should read about 83K ohms. that's off-scale on the 20K ohm setting, so your reading was OL -- good.

- with the volume at max, you had the full resistance of the volume pot (250K onms) in parallel with the resistance of the pickup. this will read just a tiny bit less than the pickup, so your pickup resistance is something like 7.35K ohms -- good.

- the tone capacitor is in series with the tone pot, so it blocks DC -- adjusting the tone pot doesn't affect the resistance measurements -- good.

your guitar seems healthy!

i'd look for a problem in your cable, or your amp.

easiest way would be to plug your guitar into a know good cable, and a known good amp. the guitar should work fine.

then substitute the cable in question and the amp, one at a time. then you'll know which one is the problem.

good luck, and let us know the results.

unk

OK, I changed the cable and that seems to have improved the situation. The tone control is definitely working. The volume control is working but it seems that when I roll it down it cuts out much sooner than the end of the sweep. Probably right below the halfway point. Maybe this is normal, just seems premature to me.

All in all the guitar does sound better.

troubleshooting by remote control is a tricky business.

there are some clues here that seem to point in a particular direction:

Hi Gang,

I got myself into a bit of trouble. I rewired my tele using Van Zandt pickups, 2 new Fender 250K solid shaft pots, a 4 way switch (Switchcraft) and a .047 Angela Tin Foil tone capacitor. I am not getting any volume unless the volume control is all the way open. Anything less and you don't hear anything. So this means no real tone either. I'm sure I did something wrong as this is my 1st attempt at electronics outside of replacing a pickup.

The pickups are not new and were working fine before. I have checked the wiring over and over again to see if I possible messed up on the switch but everything looks right.

Any help troubleshooting is appreciated.

hi BBrocks,

sometimes things that are wrong aren't obvious, or even visible.

by no real tone, i'll assume you mean there's no treble to speak of.

one thing that will cause that, is if the pickup(s) are loaded heavily with a low resistance.

if that low resistance comes after the volume control, that would also explain why the volume drops abruptly, when the volume control is reduced from max.

Melvyn is right about the meter. they're dirt cheap ($5~10) and are the second best troubleshooting tool.

you won't even need to open the guitar up, to begin.

put your meter on resistance. 20,000 ohms scale will be just fine. plug one end of your guitar cable into your Tele. turn the volume control to max. select just one pickup.

connect the probes of your meter, one to the tip, and the other to the barrel of the loose end of your guitar cable. (doesn't matter which one is red and which one black)

normally, you would get a reading of about 6,000 ohms give or take a thousand or so. but i'm guessing your reading will be much less. maybe hundreds of ohms or even tens of ohms.

if this is true, we need to determine where the problem is.

disconnect the cable from the guitar and measure between the tip and barrel again. it should read infinite. (depending on the meter, this might be indicated by a 1 in the left-most digit, with the other digits blank. or maybe the display will read OL. anyway, it's the same as when you don't have the probes touching anything.)

if your cable shows less than infinite resistance between the tip and barrel, get another cable. if it was O.K., lets move on.

you may have the connection from the wiper of the volume control to the output jack, partially grounded. if you have carbon paint shielding the control cavity or the jack cavity, the connections might be touching the paint.

or the wires (or shielded cable?) connecting the jack to the volume control, may have the insulation melted from too much heat, when soldering.

let us know what you find.

Here's what I have done this evening: I got the multimeter, a $20 purchase from Radio Shack, it's digital, easy to read the display. Had the switch set on the bridge pickup. Took a .25 inch guitar jack and used the probes of the meter on the ground and live pin of the jack. When the vol. control was closed got a 0.00 reading on the 20ohm part of the meter. I gradually turned the volume up and got about a third of the way on it's sweep and had a 19.51 reading. As I went on the reading went to 0.L until I got the the last third of the sweep and then it read 18.1 and continued to decrease to 7.13 at the top end where it stabilized. I tried the tone control but the reading did not change.

I also want to add both pots are audio pots and I used cloth shielded wiring.

BTW thanks to all for your help and patience.

troubleshooting by remote control is a tricky business.

there are some clues here that seem to point in a particular direction:

Hi Gang,

I got myself into a bit of trouble. I rewired my tele using Van Zandt pickups, 2 new Fender 250K solid shaft pots, a 4 way switch (Switchcraft) and a .047 Angela Tin Foil tone capacitor. I am not getting any volume unless the volume control is all the way open. Anything less and you don't hear anything. So this means no real tone either. I'm sure I did something wrong as this is my 1st attempt at electronics outside of replacing a pickup.

The pickups are not new and were working fine before. I have checked the wiring over and over again to see if I possible messed up on the switch but everything looks right.

Any help troubleshooting is appreciated.

hi BBrocks,

sometimes things that are wrong aren't obvious, or even visible.

by no real tone, i'll assume you mean there's no treble to speak of.

one thing that will cause that, is if the pickup(s) are loaded heavily with a low resistance.

if that low resistance comes after the volume control, that would also explain why the volume drops abruptly, when the volume control is reduced from max.

Melvyn is right about the meter. they're dirt cheap ($5~10) and are the second best troubleshooting tool.

you won't even need to open the guitar up, to begin.

put your meter on resistance. 20,000 ohms scale will be just fine. plug one end of your guitar cable into your Tele. turn the volume control to max. select just one pickup.

connect the probes of your meter, one to the tip, and the other to the barrel of the loose end of your guitar cable. (doesn't matter which one is red and which one black)

normally, you would get a reading of about 6,000 ohms give or take a thousand or so. but i'm guessing your reading will be much less. maybe hundreds of ohms or even tens of ohms.

if this is true, we need to determine where the problem is.

disconnect the cable from the guitar and measure between the tip and barrel again. it should read infinite. (depending on the meter, this might be indicated by a 1 in the left-most digit, with the other digits blank. or maybe the display will read OL. anyway, it's the same as when you don't have the probes touching anything.)

if your cable shows less than infinite resistance between the tip and barrel, get another cable. if it was O.K., lets move on.

you may have the connection from the wiper of the volume control to the output jack, partially grounded. if you have carbon paint shielding the control cavity or the jack cavity, the connections might be touching the paint.

or the wires (or shielded cable?) connecting the jack to the volume control, may have the insulation melted from too much heat, when soldering.

let us know what you find.

Here's what I have done this evening: I got the multimeter, a $20 purchase from Radio Shack, it's digital, easy to read the display. Had the switch set on the bridge pickup. Took a .25 inch guitar jack and used the probes of the meter on the ground and live pin of the jack. When the vol. control was closed got a 0.00 reading on the 20ohm part of the meter. I gradually turned the volume up and got about a third of the way on it's sweep and had a 19.51 reading. As I went on the reading went to 0.L until I got the the last third of the sweep and then it read 18.1 and continued to decrease to 7.13 at the top end where it stabilized. I tried the tone control but the reading did not change.

Did you read thru the troubleshooting guide at Guitarnuts? See the link I posted previously. I specifically found the symptom "Volume seems to do little or nothing through most of its travel then the volume changes very suddenly." ...

...with this possible solution. "The pot may be damaged but it is more likely that someone has replaced it with a linear, instead of audio taper, pot. If the control also works backwards it is likely that someone has used the correct audio taper pot but reversed the wires on the + and - terminals of the pot. The tests in the next table can be used to determine which of these is causing the problem."

There is lots more to read. Good luck with it.

Thanks, I'll go back to it and try more troubleshooting. I'll let you know if I am successful. I appreciate your help.

The other noticeable issue is that the tone conrol has no effect at all when I do have the volume all the way open. Tone does not give me any more or less treble. I am baffled by this. The 4 way switch works in all positions so I think the pickups are ok. Could the new Fender 250K pots be bad? Could the capacitor be bad? Could my soldering be bad?

The pickups are not new and were working fine before.

How do you know, whats their history?

Regarding the volume pot, could be wired the wrong way or not the kind of vol. pot you are used to using. There are "audio taper" (aka logarithmic ) and "linear taper" pots. Make sure you are using the right pot, should be the audio taper for the vol control. There is a good troubleshooting guide at Guitarnuts (for strats) which includes pretty much everything that could go wrong. If you don't have one, you would be wise to invest in a multimeter. You can check DC resistance across pickups, volume and tone pot sweep ranges, switching and grounding. They don't cost much and are useful to find out if something works before you put strings on the guitar.

The pickups were working with the old wiring, a rig that was prewired from Torres Engineering. The mid range/treble tone pot on that stopped working so I decided to take out the whole set up and replace it with the 4 way switch config. and a simple volume and tone control.

The pots are Fender 250K solid shaft pots, I don't know if they are linear or audio taper pots, they look exactly alike.

I bought a multimeter and am just learning how to use it.

This it?

Yes, but I am not using the treble bleed on the volume pot.

Hi Gang,

I got myself into a bit of trouble. I rewired my tele using Van Zandt pickups, 2 new Fender 250K solid shaft pots, a 4 way switch (Switchcraft) and a .047 Angela Tin Foil tone capacitor. I am not getting any volume unless the volume control is all the way open. Anything less and you don't hear anything. So this means no real tone either. I'm sure I did something wrong as this is my 1st attempt at electronics outside of replacing a pickup.

The pickups are not new and were working fine before. I have checked the wiring over and over again to see if I possible messed up on the switch but everything looks right.

Any help troubleshooting is appreciated.

Did you use a schematic/diagram or just unsolder/solder as you went along?

I did use a schematic that came with the switch. I also checked Specialty Guitars LLC and their schematic was the same for the 4 position switch.

Hi Gang,

I got myself into a bit of trouble. I rewired my tele using Van Zandt pickups, 2 new Fender 250K solid shaft pots, a 4 way switch (Switchcraft) and a .047 Angela Tin Foil tone capacitor. I am not getting any volume unless the volume control is all the way open. Anything less and you don't hear anything. So this means no real tone either. I'm sure I did something wrong as this is my 1st attempt at electronics outside of replacing a pickup.

The pickups are not new and were working fine before. I have checked the wiring over and over again to see if I possible messed up on the switch but everything looks right.

Any help troubleshooting is appreciated.