I've a Surface 3 4GB model - bought in Oct so always windows 10. I HAD an annoying issue where it sometimes gave me a blank screen when I tried to wake it from sleep and I would have to hold down power button to get it restart to access the machine. To resolve the original problem I re-installed windows (via the reset this PC) - this has resolved the original problem but now I have an issue with hibernation. The machine, originally, - if left asleep for a couple of hours - would shut down and when switched on would run through the "Surface" logo start-up (which reading the MS help on Power settings) looks to be what it ought to do. This means battery lasted ages and battery monitor always showed minimal use in "background" and lost neglible charge overnight. NOW the machine won't automatically hibernate. It stays asleep - will wake instantly - but overnight will show its drained significant amount of battery in background. I've reinstalled windows 10 again - and checked I'm fully up to date with everything - but this hasn't made any difference. Any ideas. I'm having to manually shut-down at the moment which is annoying.