Update
After trying all the above suggestions to no avail I was able to test with another PSU. Still no good. I was pretty convinced it was the motherboard and my mechanical hard drive then dying was the last straw.
Ive just finished a new build:
8600k @ 5.3ghz. Delidded. H115i cooler
Gskill 16gb ram @ 3200C14
Aorus 1080ti
960 EVO SSD
Corsair carbide 740 case.
My SB system served me very well. I was a little sad to see it go after so many years. I was hoping to go AMD this time round but unfortunately I couldnt wait without a functional PC any longer. I also had my doubts about AMD making up the clockspeed and IPC difference. For everything else Ryzen/Ryzen+ is a beast. But for DCS you still need raw clocks and IPC, especially for VR.