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 I knock it and wrestle with it, it sometimes starts acting normal, but that 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 fun replacement, like Stellartone or something?