How do I know if the logic board is bad?

So the girlfriend dumped a slew of water on her 20 gig 4th gen photo. I've completely disassembled it and THOROUGHLY dried it out and all seems well from that perspective.

So here is what is happening:

- if I plug it into my PB it does not respond, nor does it start to charge
- if I do a "restart" (menu + center button) with it unplugged I get the exclamation point with the battery (low battery indicator)
- if I do a "restart" while it is plugged into the laptop, I get the lightning bolt with a battery (battery is too low to be recognized by computer)
- if I plug it into the regular AC charger, I get the same results
- if I try to "restart" again, the screen goes blank and then the lightening bolt comes back eventually

I opened it up again and took a volt meter and measured that the battery is still good; I get 3.8V I think or something like that from the red and black wires of the battery. Plus this thing is only like 8 months old, so I know the battery isn't bad.

This leads me to believe that the logic board is bad b/c that is what the battery plugs into. The screen must still be ok b/c it looks fine.

So does anybody have any ideas?