Before you start prying off the back, try holding the volume buttons(up and down) and the power button simultaneously for about 20 seconds. Mine rebooted and was able to charge again. When mine went down it was at 66%, but when I got it to reboot, it was at 2%. If the battery is completely dead, you may be able to get it to reboot by having it plugged in at the time you try this. I found this suggestion elsewhere on Android Central and it definitely worked for me. I was happy that I tried it first before possibly damaging the tablet by trying to get the back off. Hope this helps!