Topic: Replacing a bad potentiometer

My volume control went bad on I was playing and adjusting it I could hear a crackling sound and it would cut out for a second, then turn back on.  Finally it just quit working at all.  I read that this is a pretty common issue with newer Ibanez guitars like mine.  Should I just take it to my local shop?

"A steering wheel don't mean you can drive, a warm body don't mean I'm alive"

Re: Replacing a bad potentiometer

It is not a difficult or expensive job. A local shop should be able to do it very easily or you could tackle it yourself, if you are inclined.

If you do it yourself, getting the right pot is important to good results. If your guitar has humbuckers, it almost certainlyhas a 500k ohm, audio taper pot as the volume control. If it uses only single coil pickups, rather than a mix, it likely has a 250k ohm, audio taper pot. If the top of the guitar is carved / arched like a Les Paul, you'll need along shaft pot, otherwise the standard type is the best choice.

A pot has 3 connections - top, wiper and bottom. Normally, when used as a volume, a signal is connected at the top, the bottom is connected to ground and the variable wiper int he middle is the output. As the pot is turned, the wiper moves, changing the resistances between signal and ground. Turned up, the wiper is near the signal connection, so there is low resistance to the signal going out on the wiper, but a high resistance to it getting drained off to ground. Turn down and the opposite is true.

Anyway, the steps are: open the access panel on the back of the guitar by removing some screws; do a quick visual inspection to see that there are no broken/loose wires and the pot value is correct (look for a printed 500kA on the back or side); Desolder the connections making a note, if needed about their position and orientation; pull off the volume knob (check for a set screw first, but many just push on); loosen the nut holding the pot in place being careful not to scratch the face of the guitar; extract the old pot; before installing the new pot heat a spot on it's case and flow a little pool of solder onto it, for grounding, as this is a high heat operation compared to the rest of the job and so, easier done on the outside. Finally, install the new pot, orient it, tighten it down resolder all connection. The last step is to replace the access panel and knob.

Roadie & Reviewer

Re: Replacing a bad potentiometer

This on again off again and crackling can be caused by dust in a potentiometer. Repairmen have a spray can of lubricant they spray on the pot to lubricate and liquify the dust inside that is causing the unwanted noise.
I would try that before I jerked the pot out and soldered in a new one.

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Re: Replacing a bad potentiometer

You can do that - open the panel, remove the pot, find the opening near the connections and spray in pot or tuner cleaner. Then give it a good wiggle to dislodge the grunge. It is a temporary measure, because pot rot has started.

In a vintage guitar, with original solder joints and correct date codes on the pots, I'll take extreme measures to keep that original pot in there.

On a daily player, swapping in a new pot might take 1 minute more than a cleaning and costs about $3. You can do it in the same time as it takes to describe it and a new pot is a definitive solution. Like a new tire instead of a retread.

If you decide to use a cleaner, remember to spray it in the hole in the pot's case, then rotate the shaft. I've seen people spray it on the shaft, back of the case or other unlikely spots and of course, get no results. Also watch out for overspray and give it about 30 minutes to dry. What at first seems like only a minor improvement gets better as the solvent evaporates and leaves lubricant behind.

Roadie & Reviewer