Do you have a local ATT tech store nearby? I would try that. It's different then the sales store. Guys seem to know what they are doing. Hopefully you are still under warranty or have insurance?? Good luck
I think it's a hardware problem. Just yesterday I had the same problem. I pulled the battery, waited for a few hours, put it back. And the first thing that came on was the camera flash.
But in my case, I think the alcohol I used to clean the trackball got in too much. I pulled the battery again, and left it for a whole night, now it's back to normal.
You should go to the local tech store. Unless you think you're capable of fixing it by yourself.