JL Audio 300/4 intermitant Amp problem

[try2fixit]

The amp produces sound out of all channels, but the rear right channel seems to go crazy at times. The audio output from that single channel seems to almost double at times on its own. It lasts for maybe a few minutes then goes back to normal. Lately it has had some popping noise too. If I turn the amp on and off this seems to clear the issue for a short drive. With all audio inputs removed and the amp powered on, I adjusted the gain on the rear channel and immediately noticed a very loud pop in the right rear speaker when the screw driver touched the knob. (It was if I was thumping a microphone) the left side has no issues. This happens Every time I touch it. I mean I barely touch the knob and a popping sound comes from the RR speaker. Any ideas on what would cause this? I haven’t opened the amp up yet… I’m thinking maybe a bad potentiometer or solder on that channel. I have never tried to repair a amp before, but have basic knowledge of common electronic components and figured I'd try...

[AKHeathen]

sounds like you are going in the right direction. most likely physically damaged pot. after checking the solder connections, go with ohms reading on the legs as you adjust it.

[Perry Babin]

Before you put any heat on the terminals of the potentiometer, you should make sure that it's not simply dirty. Does the popping occur regardless of the position of the potentiometer?

[try2fixit]

I'm not sure if it does it the full rotation of the knob. I did work it back and forth a few times the other day in hopes it would improve. When rotating it is a static/ crackel. When the screw driver 1st touches the knob its like it acts as a pickup for the amp sending a really loud pop/ thump directly to that one speaker. I didn't think of cleaning the pot with contact cleaner. I'll take the cover off and try that with the power disconnected to see if that does anything. Good idea thanks...