I think the problem with your OM is not a serious one, so I doubt that you should have the PCB changed. In that case it's easier to buy a new camera, I think Well, the chewing on batteries almost always indicates the inner short circuit - I bet the wiring got loose somewhere, contacting with camera body. Or the corrosion products shorted something somewhere - it usually results from a leaked electrolytic capacitor. Usually it's easy to find and fix.
Good luck in your repair,