how much ya wana bet it's a noisy pot.
you can repair most carbon pots but it's fiddly
brakes down to cleaning the carbon slide on the pot and the armacher.
if you don't want to take the pots apart get some 90% robbing alcohol big bottle
submerge the pcb w/pots and turn turn turn *edit*/ i dont mean spin the whole pcb in the liquid turn the pots as if they were being spun by the joystick *edit*/ move them around allot. make sure the liquid gets in it.
Then blowdry the board to get most of the alcohol out. let it sit on a windowsill or somthing for a day to evaporate anything else this should knock off most of the dirt/debry from the slide assembly in the pot.
Providing there is still good contact pressure between the armicher and the slide/contact this will repair it.