I asked this question on Yahoo Answers, but wanted to also get opinions here.

I have a Epiphone PR-5E (1998 model) that has a couple issues.
For reference, it is similar to this version of the guitar: http://imgur.com/NOI3Zgt
(same output jacks, but with the Epiphonic VI preamp)

First of all, it plays really good and sounds pretty good through an amp. The problem is that the output jack doesn't seem to turn the battery off or on. It stays on all the time...I can put a battery in on, let's say a Friday evening, not touch the thing, not plug it up or anything, and by Sunday morning...dead battery. Also, the XLR jack just outputs nothing but noise.

I'm not too concerned with the XLR jack (although it would be nice to have it functional so that I could use it directly into my church's mixer) but what I want to know is, what could I do about the jack not shutting the preamp off?