ok, so my Nexus7, 4th one and finally with no screen lift, is crapping out on me today. Was talking to a buddy and flipping through magazines and it went black. would not power on. plugged it in to my computer thinking maybe the battery died, although i saw 19% on the screen. i got the battery charging screen, so i powered it on. it worked for about a minute. then, black but with what appeared to be random active pixels, then nothing again. anyone have any ideas? it's stock.