I accidentally left my hudl disconnected & switched on & it ran the battery flat. I re-charged it & switched on but its stuck on "powered by android". I've tried holding the on/off button and the volume button but I can't switch it off or find out where the battery is (looks like you can't open it). I'm going to see what happens when it eventually runs down again but has anyone else encountered this problem and what can I do to fix it?