Alright guys, was hoping for a bit of feedback on this. I've been working on a bass for a friend, and after a lot of fairly involved work - it was a body transplant that nothing lined up on, neck, bridge, pickups etc that ended up requiring a lot of dowelling, filling and routing - and getting it all done in a couple of days for him, there's a grounding problem that's driving me mad.
There's the standard crackle/pop when you touch any metal part of the bass that signals an earthing problem, but bizarrely I have complete continuity from every component to earth (I've checked with a multimeter). No breaks at all.
WEIRDLY, there is a crackle/pop when you touch the screws that mount the pickups to the body which aren't connected to any conducting material. Also, weirdly, the polepieces on one part of the split pickup also cause a crackle when touched (but not the other)
I've never seen this before and it has me at my wit's end. I suspect the pickup may be junked (it's a Duncan Quarter Pounder). I've checked it with a multimeter and I can't get any continuity between the solder joints on the pickup itself but I don't know if that's because it's wax potted or not.
Any ideas? I've tied a lot of time and money into this and I really need it back in order to eat! I'd considered resoldering everything but I'm fairly certain it's a pickup problem now.
And here's the link in case the embed doesn't work: https://www.dropbox.com/s/s37ykukpy6uhucr/IMAG0218.jpg
Does hum/noise start or stop when you touch the metal parts?
Does hum/noise happen when you touch those pole pieces?