iPhone 3G won't turn on... help?

My daughter's iPhone suddenly stopped working.

We thought the battery had died so we tried charging it over night. The next morning it was still dead. We tried a different charger thinking maybe the charger was bad, but still nothing. We tried plugging it into the computer, outlet, everything, and nothing works. We tried different cords, nothing.

The phone is completely black. If you connect it to the computer (or plug it into the wall) nothing happens. Nothing lights up or displays on the screen and neither the computer nor iTunes sees the phone. Hard reset does not work either. The phone was still under warranty, but it got a little bit of water on it a long time ago, and they will not warranty it. It has worked fine for months since it got a little water on it. Only one of the water sensors shows it got wet. It had been working fine until it suddenly just died.

To make matters worse, I updated the software on my iPhone and now it is useless. It is stuck in recovery mode and errors out every time I try to restore it. So now we have two iPhones that are permanently in paper weight mode. I bought my daughter a new cell phone (non-Apple) and ironically now it would be nice if I could get her old iPhone working to use as a backup while mine is dead.

Does anyone know anyway to fix this phone??? Or the other one...