Hey guys - a few of you might know that I've switched from the sales side of things at GC, to working in guitar repair there. I was working on a customer's guitar this afternoon, and ran into this issue that I just can't diagnose.
It's a 2007 American Deluxe HSS Strat with the S1 switch. The guitar was brought in with an intermittent bridge pickup, and some electronic hum. Somehow, the "hot" lead on the bridge pickup was never actually soldered to the switch, and had only manifested itself as a problem recently (the customer assures me that the pickguard had never been removed before, and the soldering is clean enough to look like a factory job, so I'm inclined to believe him). I fixed that, and now it works reliably.
The hum issue is killing me, though - when using the bridge humbucker, there's noise roughly equivalent to what you'd hear from a single coil, so my first thought was that maybe the coil split was wired incorrectly. I checked both coils, as well as the full pickup, with a multimeter, and everything tests correctly. Comparing against Fender's service diagrams for this model guitar, everything is wired correctly. There are no visible shorts, and the multimeter says that the pickup is working correctly.
I did notice that the level of the hum changes when the guitar is moved around, like moved closer to flourescent lights, for example, so maybe some extra shielding is in order? The whole cavity has shielding paint applied to it, though, with a ground screw, and the bridge ground is fine. The neck and middle pickups, which are stacked humbuckers, are dead silent - no hum at all.
What the hell could I be missing here?
Is there any way you can compare it to a similar-output humbucker in a different guitar? I've never played the Fender noiseless pickups extensively - the original ones were so bad I haven;t wanted to - but it's not unheard of for a noiseless singlecoil to actually be quieter than a full humbucker, so it may just seem loud by comparison...?