Question 5080 won’t display

Jan 31, 2025
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Been at this all day now. The 5080 powers up all lights and fans spinning but won’t display. Bios posts normal.

The build was completed last last week borrowing a 3080 as a temp solution, using a riser cable due to hy70 case.

What I have tempted:

Change PCie to force 4.0 as the riser cable is 4.0 even though the the mobo is 5.0
Reseated everything multiple times
Reseated 3080 and confirmed fine
Booted onboard graphics without issue

Last thing I think of flashing the bios (it was updated in dec)

Anyone have ideas?

Edit: I will be checking it in my mates build later on when he finishes work if all else fails
 
Do what Gaidax suggested. From what we know, PCie 5.0 is VERY sensitive to signal degradation and PCie risers are already a common failure point on 3.0/4.0.
Wouldn’t running pcie slot at 4.0 eliminate that tho cause it’s confirm to work on 3080. Only way I can test it without riser is when my mate finishes in a few hours which I’ll do it
 
Wouldn’t running pcie slot at 4.0 eliminate that tho cause it’s confirm to work on 3080. Only way I can test it without riser is when my mate finishes in a few hours which I’ll do it
Who knows, it's a new GPU gen and it has new PCI-E gen used first time for it. It all in theory should be compatible, but who knows what kind of defects there with implementation are actually.

That's why we should try to eliminate all the exotics like that riser cable, even if in theory it should not be a problem in 4.0 mode.