I bought this secondhand about a year ago, and love it to bits, but every now and then it develops a hum which can be made to go by unplugging/replugging the lead or twiddling the pots. The pots are a pair of stacked volume/tone for each pickup. I’ve re-soldered all of the joints, which seemed to work for a while but it’s getting worse again. I’m sure I read somewhere that the loom isn’t right on these and there’s a capacitor missing, and was wondering if that might cure it. Anyone got any ideas, please