Pickup problem on C6 neck

[Shawn Canning]

Any one know why the output level on my C6 pickup (Sho Bud Proffesional) may have dropped dramatically suddenly? Loose wire? Or, are there larger forces at work trying to spare the audience my playing of the C6 neck?
Joking aside, over the weekend during a show I lost output on the one neck. If I toggled to the C6 and opened up the volume all the way I could get some sound, but nothing close to the signal out of the E9 pickup. My apologies if this is standard electronics trouble shooting stuff, I've clearly got a lot to learn. Thanks in advance.