Fender Ultra II Precision Bass with intermittent volume knob

[JD Campbell]

My Fender Ultra II P-bass developed a problem with the volume knob- as I turn it clockwise it puts out low volume until it reaches around 11 o'clock then the volume increases (jumps up) drastically. Is anyone experiencing this, or have any thoughts on what may be happening? This knob also has a stacked detent button on top which works to switch from active to passive mode.

 

[micguy]

Potentiometers do fail - the wiper is likely not making contact along it's whole rotation path. If that's the case, you need a new pot.