Naturally I assumed this was a DOA motherboard and the store replaced it immediately. To my surprise I'm having the exact same issue with a new board. I've tried 4 different GPU's so far. Display ports work fine on slots 2-4 and DVI works on all slots.
I've unplugged everything from the board except the GPU, CPU and 1 stick of memory in slot A1. I've also put in a stick of memory that is on the QVL in this configuration and the problem persist.
I'm not sure how the architecture works could I possibly have a bad CPU?
Thanks very much for all your help.
MB: Asus ROG x399 Zenith Extreme
CPU: Ryzen Thredripper 1920
CPU Cooler: Fractal Design Celcius S36, fans switched out for Corsair ML120
RAM: 8x DDR4 G.Skill Trident 8GB (currently running at 1066Mhz)
GPU: 2x Asus ROG Strix 1080ti
PSU: Corsair HX1000i
BOOT DISK: Samsung 960 m.2 1TB
STORAGE: 4x intel 540 SSD 1TB in RAID0 using Windows Disk Management (because raid over the board is non-functional, more on that later)
Case: Corsair Obsidian 750D
Case Cooling: 2x Corsair ML140 intake (plus 3 from cpu rad cooling), 3x Corsair ML120 exhaust
Fan control: Corsair link via Commander Mini Pro case keeps positive pressure from 400rmp to 2400rpm