My 2g ipod touch was working when I got home, it had about half battery left. After about 20 minutes, i tried to open it, but the screen stayed black. I tried to turn it off and charge it, but when i plugged it in, itunes didn't open and it didn't detect the ipod touch. I left it open overnight a couple of times by accident, but never more than 48 hours. Any ideas what might be wrong with it?