Presence knob not adding any brightness on one channel

[b0nkersx]

My presence knob on my Road King II in channel 4 suddenly doesn't do anything in any mode. I can strike a chord and turn the knob from full left to full right and not hear a thing differently. There's no scratchy sound or anything if I turn the pot. i.e., it doesn't sound like a dirty pot.

I thought it may have been my ears at first, but every other channel has its presence knob working as it always has. For example, if I strike a chord on channel 3 in vintage and turn the knob from full left to full right, there's a considerable difference.

Is this a bad pot? The preamp tubes are running at about two years old but I'm not even sure if that even matters for the presence knob.

 

[fluff191]

Only way to know the pot is bad is to measure it. It does sound like the pot sh!t the bed though.

 

[b0nkersx]

Would that require a multimeter?

And do you know if replacing the pot myself would void my warranty? The closest authorized tech is 2 and a half hours away, and has a pretty slow turnaround time.

 

[fluff191]

Yes that would require a meter.

And I can only speak from my experience, but when I did my presence pot change, I asked about the warranty when I was ordering the pot from Mesa and they said as long as I was using a Mesa pot I was good to go.