How to fix Windows Mixed Reality headset that won't wake up

[Windows Central]

Display inside your WMR headset won't turn on? We have some potential fixes.
Windows Mixed Reality (WMR), the PC-based VR system, is relatively easy to set up compared to HTC Vive and Oculus Rift, but you might still run into a snag here and there. One issue commonly reported is that the headset doesn't "wake" when it's needed and won't show any sort of picture on the internal display. If you've recently plugged it in or switched ports, a PC restart might take care of the problem. Read on if you're still stuck with a sleeping headset.

Full story from the WindowsCentral blog...