Curing a Pot Problem…

Posted by: Daniel R. Lehrman Posted in: Guitar Repairs Upgrades

One of my cohorts and friends who also blogs about guitars wrote an article about potentiometers. Buck from Buck’s Guitar Modifications posted a nice article about rebuilding pots. I don’t have a beef at all, in fact I agree with him very much. It actually caused my one half of a working brain cell to come to life! I grew up in the ’60′s!!

They certainly don’t make pots or potentiometers the way they used to. Do you know what a pot is?

potentiometer-breakdown

Potentiometer-Breakdown

Using the picture above: the blue needle would be the knob that you turn, as in a dimmer switch or volume knob. The yellow horse shoe shaped strip is actually a thin strip of metal that the blue needle swipes across (back and forth) when the knob or blue needle is turned. Basically if the #1 position is all the way to the left that would indicate the off or least amount of power position. As the knob is rotated to the right (clockwise) it increases the output of power or juice. As in the picture, the blue needle would be one half open or allowing one half power. This upgrade or repair or explanation is one of many listed at GPC.

Note: Think of it as a dimmer switch or volume/tone control, If the knob is to the left the lights or volume would be low, as it rotates clockwise the lights or volume will increase until it hits full power at full clockwise position. Fairly simple in theory. And, I may add, this is a real simplification of one of the many duties a pot can have.

So, Buck is saying when he talks about having a flat spot at the #7 position on the volume control or pot, he means that the yellow metal strip is worn out at that position (#7) and does not make contact at that particular spot with the blue needle or knob. So no volume at #7, volume at every other position.

For the most part, at least on a volume switch, it is no big deal, play any position other than #7, if you want softer or louder. Other pieces of equipment that use pots may not be so forgiving. Most of the controls on a guitar are pots, cars have pots all over them, it’s hard to justify a bad pot on a car since it may affect your safety. Your wah pedal has a pot in it, when you manipulate the pedal the pot is going back and forth on the yellow metal strip.

It is really hard to fix a worn spot on a pot. I would not advise it on a valuable piece of equipment that you can’t find a new or good pot for. I have had some success in the past flowing some solder over the worn part of the strip. Some success is the key, it takes a bunch of practice at soldering to be successful, and some luck.

Hopefully, after you read Buck’s article and Guitar Players Center’s breakdown definition of a potentiometer, you will have a better overall understanding of potentiometers. We sure appreciate any comments or further info on pots. Do you have any ideas on repairing a potentiometer, let us know. As you know, if you need help, Myself or Buck are willing and able. If you enjoy this post please Share It.


4 Responses to Curing a Pot Problem…

  1. I need one of those to juice of my brain sometimes (maybe you need one for your 1/2 working brain cell, Danny).

  2. Danny, Thanks for the support. This is the first pot I have rebuilt. The solder idea sounds cool I’ll have to try it. I tried several pots close in value ( 25k 18k) I lost volume with both. Iwas told by a electrial engineer friend that when you change pot values that you have to change resistors tied to the pot circuit ( WAY BEYOND ME )But a good piece of advice to know Buck

  3. I ran into this problem after a humbucker install for an SG type guitar (Washburn WI64DL). The new neck tone control does not work at 9-10 position, but at all others and it makes the guitar go ‘dead’ at 9-10 (no output, which must mean the signal is shorted and cannot get on to the jack.
    I will replace the $7 pot (a good brand) and not worry with it. But I suspect that I overheated the back of the pot when soldering one lug to the back as needed. I bet I accidentally melted or damaged the ‘track’ the wiper travels across when I turn the knob.
    So, to me the best lesson to take is: solder a small tab on the little square recess on the pot edge and then solder any wires to the tab…. and use an alligator clip on the tab at the pot body as a heat sink if you want to be cautious.

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