I've been using my rift for over a year now, and I experienced this problem some other times, but I always managed to solve it with a DVI-HDMI adapter or by switching ports. Now I spent a few hours trying to solve it, but I couldn't. Last week it all worked well, today the Rift displayd a blank screen (the light is orange and goes away when I put my face close). After reinstalling the Oculus drivers, now the Oculus center says it can't see the Rift attached to an hdmi port! I tried various combinations, with the aforementioned DVI-HDMI adapter, with a DP-DVI adapter, and directly to the HDMI port. I used my main 4k television attached via the HDMI port or the DVI-HDMI adapter, then unplugged it and tried with a spare 20" DVI monitor, to no avail. I have an MSI GTX1070, an ASRock Z170 mainboard, an i7 6700, 16GB of DDR4-3000 and a 500GB Samsung EVO SSD. Latest Win 10 freshly installed. I've attached a log file.