Hey guys. I've just finished my 2nd build. I put a p90 in. Sounded great in the dry run before finishing. So a couple of issues now i have it all back together. I earthed the strings via the tail piece to the out jack and now when I touch the strings I get alot of amp noise. It's worse with the volumn down. The tone pot' s not working as well as it did in the dry run either. I tightened the pot's pretty tight. Could that be a problem, have I damaged them?, and what about the earthing?