My audio cassette deck has a panning knob (left/right), which I assume regulates the strength of the two channels of a stereo signal. When I turn the knob, there is a rustling sound and the sound is intermittent. I have to manually push the knob in some direction to have both channels make contact.

Is such a knob a simple potentiometer that I could replace? Or is there some sort of maintenance to be done on it? I have already used compressed air in various angles directed at the base of the part and at the small openings around knob itself.

Edit: description of the knob in question

Edit: view of the PCB on which the "potentiometer" in question rests