I bought the 3080 XC3 Hybrid to replace my 2080 Super Hybrid but after swapping, I get no signal and black screen.
I have tried all 3 DP slots as well as only using an HDMI cable with no success. My Crosshair VIII Hero has a Q-Code LED on-board and the code it is showing just says there is a problem on VGA.
 
These are the full steps that I have tested before starting an RMA request.
1) Due to a possibility of the vertical riser on the Hyte Y60 PC case possibly being defective or a PCI-E 3.0, I have taken the riser out and directly connected the 3080 to the PCI-E 4.0 slot on my motherboard. This changed nothing. 
  2) I have added an additional power cable to test if there was insufficient power draw from one 2x 8-pin cable, this yielded no change. All fans and LED logo on the 3080 Hybrid spin and light up just as it had with the single 2x 8-pin connector. 
  3) I have ensured that all cables are properly connected and the card was seated properly and securely into the PCI-E 4.0 slot. 
  4) I have uninstalled the graphics driver for the 2080 in safe mode, powered down the PC, installed the 3080, booted up the PC and tested two different display port cables in all 3 display port outlets on the 3080 as well as used 1 HDMI cable with no change, there is still no signal being sent with all fans spinning and LED logo lit up indicting that the card is receiving power. 
  5) I have swapped out the 2080 and 3080 five times during different tests and the 2080 has always worked and sent signal so there is no defect on the motherboard, unstable power or improperly seated card and no loose cables. 
 
Since these tests were done, I was informed through my service ticket to follow through with an RMA and I have received the new replacement today (brand new just as the first one was). I plugged it in and still get no signal and my 2080 still works perfectly fine. 

arthurz21
Could you try the method mentioned in the first comment in this Reddit thread? (turn on the system with no GPU and let ASUS mobo cycle through LED debugs a few times until stuck at white light again, turn off pc and insert GPU and turn on pc)
 
This method worked for me a while back when my ASUS motherboard was stuck in the white VGA debug code.

Thank you. I will give this a try.

ty_ger07
Have you made sure that the motherboard is not using secure boot? That would he a sure-fire way for it to hate the GPU swap.

This doesn't work for me. There isn't an option to disable it. It is enabled and greyed out. I can not deactivate it. 

arthurz21
Could you try the method mentioned in the first comment in this Reddit thread? (turn on the system with no GPU and let ASUS mobo cycle through LED debugs a few times until stuck at white light again, turn off pc and insert GPU and turn on pc)
 
This method worked for me a while back when my ASUS motherboard was stuck in the white VGA debug code.

This method unfortunately does not work for me.

You have to disable secure boot in the motherboard UEFI, not just in Windows. Did you do that? There is some functionality in the motherboard UEFI firmware where you have to specifically select to reset the secure boot keys.

OP, do you have CSM disabled and a GPT boot drive?  Have you tried another motherboard slot?  Have you tried removing and reseating the CPU?  Have you tried the GPU in another machine?