Mine was acting tempermental today. Wouldn't seem to power up, even using the "plug it in and hold power til it turns on" method. I ended up popping the back off (get a fingernail into a corner or whatever, and carefully pop it open. Carefully unplug the battery for a minute, plug it back in, then plug the tablet in, hold power down and hope it comes back on. Took about 20-30 seconds holding down, but powered back on. Now I'm just backing up the pictures to cloud storage, and making a list of apps to restore, and which ones I don't want back, just in case it acts up again, I'll do a factory restore just to be safe before calling in the warranty.