I know why the Nexus 10 won’t turn on. It’s the same problem on the Nexus 7. The Kingston MMIC breaks after a few years. You basically have to open the tablet, buy a new MMIC chip from a different manufacturer, resolder it onto the board, and then reflash a compatible Android build onto it. I’m an electrical engineer and still don’t have the energy to do all that. A new tablet is like $100.