If you aren't getting video to your Rift, it might likely be an issue with your HDMI connection. How is your Rift connected to your PC, specifically, the HDMI side? Also, just in general too (USB 3.0 or 2.0 for the Rift headset?)
A quick check on both ends of the Rift cable to make sure it is seated in the ports well would be advised.
Also, could you post your PC specifications?
PC Specs:
Intel i7-6700k @ 4.5 Ghz
Gigabyte Z170X-Gaming 3 Motherboard
RTX 2080 Ti - MSI VENTUS
16 GB CAS-10 RAM @ 2400 MHz
Startech 4-port/4-USB controller add-on card
850W Corsair HX850 PSU
4-Sensor, Roomscale Setup