Hey Mikey,

Its doubtful that a PBG neck pup is broken such that wont work on the G string but will work on the other strings. This is because the neck pup has a ceramic bar magnet that passes along the base of all six of the steel pole pieces for the whole pup. If there was a break in the windings, the whole pup would not work. The magnetic field created by the ceramic bar magnet should encompass all of the strings, even if there was a break in one of the pole pieces (which is not likely to have occurred).

Its more likely that you have a dead G string, or its muting on the nut or the saddle for some reason.

I am happy to be corrected by a smarter individual.

If you are in Brisbane, let me know as I have a spare PBG neck pup you can use/test.