Pickup Problems

[BigBubbaBrown]

I bought an electric guitar at an auction last night. I plugged it into my amp to try it and not a sound came out. After running my keyboard through it I ruled out problems with the amp itself and the cable, then I took the guitar apart and checked all of the wires. Everything's in place and the wires themselves seem to be in good condition.

I was operating under the belief that guitar pickups are simple transducers then my friend's boyfriend told me that modern ones are a magnetic resonator coil system, which I know nothing about. Due to limited space in the cab of my truck and the unwillingness to carry either object in the bed of my truck I had to bring it home with the guitar leaned up against the amplifier (brought the guitar to my parents' from the auction, then picked up my uncle's old amp and carried them the last six miles), which I was told could have switched the polarity of the magnets.

I can't really afford to buy a new pickup to install as I had to borrow money from my dad to buy the guitar so I was wondering if there was any way to salvage the existing one. I've read elsewhere that it's impossible, but then again those places are what gave me the impression that it was a simple transducer. Maybe using a set of four magnets to alter the polarities of the coils?

EDIT: After posting this I took a magnet off of my fridge and ran it over the pickup. The top coils repelled the magnet while the bottom ones attracted it, leading me to believe that the polarities were not reversed by the magnet in my amp speaker.

Given that, what are some other potential problems and is there absolutely any way to salvage it without spending $50 for a replacement?

YET ANOTHER EDIT: At the suggestion of my friend's boyfriend I passed my cell phone over it while calling it. With amp distortion off and volume to full there was no sound. With distortion on it picked up. I put one of the strings back on to test, and I only get sound when distortion's on.

The humbucker, if I've been given the proper name for it, isn't living up to its name. There's a constant buzz that gets louder if I take my finger off of the string. There are two knobs (they're not labeled, but I know one's the volume. Don't know what the other is) that act more like switches. The volume stays the same whether it's at 10 or 3, then cuts off completely at 2 or 1. I left the top knob to full and turned the bottom one to 0 and that got rid of the buzz, other than what the amp makes with distortion turned up and nothing plugged in, but it also got rid of the sound. I reversed it with the exact same result. It seems the knobs themselves don't really do anything in the 3 to 10 range.

When I had it apart I checked all of the wires and they're all in place. None of them have come loose and each wire is firmly connected to a lead. However, I noticed in diagrams of dual humbuckers that there's one wire for each set of coils and in my setup there's only one wire coming off of the bottom set. Am I missing a wire? And is that contributing to the noise?

Also, if I want to use the guitar without distortion will I need a preamp? My keyboard works fine without distortion, but it's a line out so I don't know if the problem is in the guitar or if there's a problem in the amp that can't be detected when testing with a powered instrument.

Edited April 7, 2011 by BigBubbaBrown

[maxtor2290]

BigBubbaBrown:

Without knowing what kind of guitar it is (Make, Model, Serial Number, and etc) it is difficult to attempt a diagnosis.

If I am understanding correctly, the pickups are passive and not active.

It is unlikely that the guitar leaned against the amplifier, even with the pickups directly in front of it reversed the polarity of the pickups. The magnetic filed, while strong when very close to the magnet on the speaker, has a limited sphere when there is no electricity applied to it. When plugged in, the field intensifies and its sphere gets bigger.

All of the difficulties mentioned in your post can have a wide range of possible causes. It could all very well be in the pots. They could be dirty or fried inside. (Common)

It could be that someone has previously re-wired the pickups incorrectly and created the problem. (Common with used instruments)

And yes, it could be the pickups themselves. (Not Common)

You need to start with an understanding of how it is supposed to be wired and function then move to testing each component individually with a meter.

The pickups themselves are likely coil pickups, in which the polarity of the pickup is determined by the flow of the small amount of current through the circuit from the amplifier.

I am sure folks here would be glad to help if some additional info about the guitar and configuration was available.

max

[AlexOConnor]

Pickups themselves don't really... "Break", not unless you unwind them...

First port of call is find the wiring technical drawing and resolder all the joints. Some of the guitars that come through my workshop have no visual signs of poor wiring but almost always a resolder fixes the problem.

Another reason that pickups sometimes cease to function is because people move the screws to change the distance between the strings and the pickup (normally because the neck has moved and their worried about playing with the truss rod)

Either way - the only time i've ever HAD to replace pickups is when they are so dirty and dusty that they can't be cleaned.

Hope that helps - If you provide some pictures, I can help

[davidmichael]

100 to 1 its the output jack on the guitar.try wiggling the cable in the jack as the strings are vibrating on the guitar,or reapeatedly insert and remove the chord,and see if you get any sound.that is the most common and probable thing to break on a guitar.