My suggestion, Go take it to a NRS and have them look at it...

Today I was sending a text message and my phone just completely shut off, the battery wasn't even that low. So I figured I'd just turn it back on, it didn't turn on.. so then I took the battery out and put it back in, it began to turn on and did the screen that is white and says i860, then it just went to white. I tried it a few more times and it still wasn't turning on. So I left it alone for about an hour or so and tried it again, but it still didn't work. I also tried charging it and changing the battery, there's nothing about it in the user's guide... any suggestions?