I know it's been 8 months, but I'm just curious if you ever found a solution. I stumbled across this post after running into the same issue. I'm running Windows 10 Technical Preview and just did a clean install on a new SSD. I was expecting it to boot much faster, but that hasn't been the case...
I'm having the same issue. I have my computer set to never sleep, but the monitor turns off after 15 minutes. It then comes back on and just displays a black screen with the mouse cursor. It will stay like that for hours and never actually turn off. I'm not using a display port connection...