You dropped it into a river? That's very unclean water. If it's still not working after a battery swap, then when it dried out it probably left particulate residue on the inside on the electronics and it's causing something to short circuit.
Something you could try is taking the battery off, removing the sim card and any SD/Micro SD cards you have in it, and rinsing it with distilled water. Distilled water is pure water, i.e. no particles in it like dirt or salt etc. After rinsing the phone for as long as you feel is necessary, shake it gently to dry it off, and use a towel or some other kind of cloth that doesn't leave residue (no paper towels!) to dry it off as best as you can. After that, shake it a little bit more, towel it down again, then let it sit around and dry off. Don't put a fan or any heat on it or anything, just let it sit for a while.
After that, put the sim/SD/Micro SD cards back in and reattach the battery, and hope for the best.
Good luck.
Quote (SalvationDG @ Jan 27 2011 01:05am)
Its broken.
Just take it to you Carrier and say you don't know whats wrong.
Phones have little stickers that change color when they get wet, so the carrier will probably know it was dropped in water, and that will usually void any warranty.
This post was edited by bentherdonethat on Jan 27 2011 12:08am