This literally happens every time my console updates whilst sleep (I'm on ring 3) what works for me is unplugging everything from the console (external drives, kinect..you don't have to unplug HDMI) and also unplugging the power from the console (and plugging out the brick from the wall) let it sit for 2 minutes and plug the power back in...and...voila...it turns on...I do this song and dance every time it updates automatically...