so i have been trying to figure out a similar issue im having i almost gave up but i bought an evga pci riser cable the one the tech from evga said would work with my evga rtx 2070 xc ultra and i also have a few thermaltake risers and i cant get it to work the gpu is brand new and works great if i plug it directly into the pci-e slot but if i try to use any risers it wont even give me a splash screen .. when using the riser i turn my pc on and it wakes my monitors up and then they instantly go right back into standby mode like my pc isnt turned on ... i have the thermaltake p5 case so not using the riser makes the case kinda dumb to look at i have tried it in the other two pc's i have which both run great and it doesnt work in any of them my current pc that i want to use the riser in is the p5 case with threadripper 1950x, asus rog strix x399-e gaming mobo an hx1000 watt corsair psu , all brand new and working flawlessly as long as the gpu in slotted directly into the mobo and not into the riser cable... i have tried everything and cant get it to work and i really hate to rma an absolutely great running 2070 it even overclocks amazing ... oh i have tried the msi 980ti i have in the riser and it works great and so does the gtx770 and gtx 950ssc i have it just wont work with the rtx 2070 i have talked to evga and asus and neither can seem to figure out the issue? idk if maybe something in the bios needs changed or what but its very frustrating having a nice system and case and not being able to vertically mount the gpu .. if you know the P5 case then youll know what i mean by how it looks dumb without the card sitting upright... i thank you all for any and all imput you can offer me to try   :) thank you for your time :)

RMA'ing the card won't do any good. The next one will behave the same. Don't use riser cables. Or, if you must, keep trying various high quality/highly recommended riser cables until you find one which will work for you. The problem you are having is with signaling frequency, timing, and noise causing the card not to initialize. You can try forcing the PCI-E generation in your motherboard BIOS down to a lower generation and see if that helps the card initialize, but that's not a great solution. The best solution is not using a riser cable.



If the signal pairs fall out of spec, it won't initialize.