Pbass-style pup has less output over one half of its poles.

[Jerry_B]

I've just acquired a Westone Spectrum LX and it's neck pup is essentially a Pbass type but with bigger poles. At the moment the D and G strings sound much quiter than the others when played. I've unscrewed it from the body and flipped it over to see if there are any loose wires, but it all seems ok (although the pup itself is sealed with a dob of plastic-looking glue at four points). I've had a look at the pots and the wiring there seems ok, so I'm wondering what the issue could be. The bass wasn't in all that great condition when it was delivered, despite having its own hard case, and was generally cruddy with some evidence of rust on exposed painted metal parts, and some of the poles on the pup were a bit tarnished. So I'm wondering if something has rotted somewhere, or whether it just needs all the electrics having a squirt of contact cleaner (which I haven't tried yet).

 

Any ideas about what might be going on would be much appreciated. I have a few regular pbasses but have never had this issues with their pups. 

[MartinB]

If there are separate magnets for the A/E and D/G sides of the pickup, the D/G one could have been de-magnetised. I had a new bass arrive with a G string that was a quarter of the volume of the others. It wasn't the strings - if I turned the pickup 180 degrees, the E string became the weak one. In theory a pickup can be re-magnetised, but in my case the manufacturer just replaced it since it was new.