Empty-sounding JB

[Jay 77]

I have (I think) an old JB in my Charvel, and two single coils that i'm not sure which model (they have hex pole pieces). My problem is that when i switch to the JB only, the sound is very empty, light, and trebley. It used to just wail. Switching to either of the single coils brings the oomph back, and the tone knob works just fine with them. I plan on pulling it apart on the weekend, so should I consider this a potential wiring issue (since i'm pretty sure the pots are fine), or has my trusty old JB crapped out on me after all these years? Any help would be great.

[Reckless Abandon]

Check the wires. Something may be touching or come loose. Check the wiring first.

[Jay 77]

Thanks. That's our plan first, so I hope the wiring takes care of it all. If not, I guess I'll be in the market for a new one. When I take it apart, I'm going to get all the serial numbers because I'd like to make absolutely sure what pickups are in this guitar & the specs on each of them. The single coils don't look like anything on the current site here. They have hex-shaped instead of flat poles. I remember them being Duncans when I first got the guitar ('93) but I have no idea what models they may be.