Hadn't used it for about half an hour (not unusual for me). Got it out of my bag, and it didn't turn on, I had put it to sleep. I tried the manual re-boot. Nothing. Then the base of the back got insanely hot, and just as quickly went cold. So I left it overnight, and it won't do anything. Turn on, connect with a computer, charge from a wall socket. What could be up with it? Any help appreciated.