Hi! I think my Fender 58' Avri P-bass needs a new tone pot. It suddenly stops working. I stays at "full" or "open" (100% tone) no matter what. If i turn it up or down it makes a scratching sound and doesn't work at all. If knock it and wrestles with it, it sometimes starts acting normal, but it doesn't last for long. Is there an easy fix, or do i need a new one? If i need a new one, do you have any suggestions for a good replacement, like Stellartone or something?