Hrm, the Oculus forum just killed the reply I sent a few minutes ago (asked me to log in again even though I had just logged in before starting to reply). Anyways, I just had that "black screen of death", too: Put the HMD down for about half an hour or so while doing some coding. Wanted to test again, all black. Power LED was green, the white LED above the Oculus logo (on the front plate) was also white. But no image, just black.
Disconnected from PC, reconnected. Nothing helped. I did try holding the power button for longer periods of time - but either it wasn't long enough, or something changed with the different things that I have tried - eventually I tried for 15 seconds (hold button, hold button, hobu, hobu) ... and the Oculus logo appeared. Now it's working again.
That was strange.
I kept having this issue and after much trial and error discovered that it was the pass through that was messing it up. To fix I removed everything attached to my oculus then attempted a restart. It came up and I was able to turn off pass through and I have not seen it again.
Anyone got some good fixes for this? I too am having the issue now. I was playing PCVR via Virtual Desktop and my HMD just went black. I have restarted it several times, Factory Restored as well a number of times. And Now It wont load the pairing screen. I can see the Charging Icon, The Boot Logo and three loading dots after booting for all of a second before black screen. I've tried everything to get it working again.