This just started last night, if I hit the power button to put the SP3 in sleep mode, or let the screen turn off on its own, and leave it that way for longer than a few seconds I can not get the screen to turn back on without holding down the volume down button and pressing the power button for a few seconds. That turns it off and I have to do the same thing to turn it back on. Booting is also now taking about 10 times longer than it did before. I just did a restore back to Windows 8.1 using an image recovery, one that I have used multiple times. Edit: also if I restart it, it just turns it off... Edit #2: I power it off it randomly comes back on.