Guitar Electronics Troubleshooting: Fixing Scratchy Pots, Dead Switches, and Hum

Guitar electronics are actually quite simple — but they can develop problems over years of use. Here's how to diagnose and fix the most common issues.

Scratchy Volume or Tone Pot

Symptom: Crackle or static when turning the volume or tone knob.

Cause: Oxidation or debris on the resistive track inside the potentiometer.

Fix: Spray a small amount of contact cleaner (DeoxIT D5 is the standard) into the pot through the access holes on the back. Work the pot back and forth repeatedly. Most cases are resolved immediately.

If it persists: The pot may need replacement. Standard pots are inexpensive and solderable with basic skills.

Dead Pickup Selector Switch

Symptom: One pickup position produces no sound, or sound cuts out in certain positions.

Cause: Switch contacts oxidized or mechanically worn.

Fix: Same as pots — spray contact cleaner into the switch, work it back and forth. If no improvement, the switch needs replacement.

Output Jack Crackle

Symptom: Crackle when the cable is moved at the jack. Or intermittent signal dropout.

Cause: Bent or oxidized jack contact. The spring contact may not be making firm connection with the cable tip.

Fix: With the cable unplugged, use a small flat screwdriver to gently bend the contact closer to where the cable tip sits. Clean with contact cleaner. Replace the jack if the problem persists.

Persistent Ground Hum

Symptom: 60Hz hum that changes when you touch (or don't touch) metal parts of the guitar.

Cause: Grounding problem inside the guitar. The ground connection between bridge, strings, and electronics completes a circuit through your body. Broken ground = hum that goes away when you touch strings.

Fix: Inspect solder joints at the output jack, volume pot, and bridge ground wire. Reflow any cold or broken solder joints.

Need Professional Help?

Our Pro Concierge can help you decide if a problem is DIY-fixable or needs a tech, and can connect you with resources in your area.