Mine was drowned during a tube ride down the Chukka Chukka River in Jamaica. **bleep** ziplock bag did not work!! Any way, it only works when the usb is plugged in. Can the battery be changed on this thing?
Sorry to here about that. The Fuze can be taken apart and disassembled (see here for tips & pictures), but I believe the battery has soldered connections (see last photo), rather than plugging in like a cell phone battery on the e200 series. For some, soldering the wires would be no problem, but finding a replacement would be difficult. You might be able to find a DOA unit (like with a bad LCD for instance) on E-Bay to scavange.
Chances are though, that if you take it apart, there is some moisture somewhere shorting it out. I’d try taking it apart as far as I could, then sealing it up with dry rice for a week or so to soak up any residual dampness. That may be your only problem.