Cpu, ram and rear NVME eliminated.
Ok, it's onto the Gfx now then.
You're going to have to strip the system down and build it back up outside the case and plug the 3080 directly into the motherboard.
Just do it on a cardboard box preferably, do not do it sat on carpet or fabrics.
Something you just have to go through here while trying to find out the cause of your problems I'm sorry to say.
If it's still crashing outside of the case and plugged directly into the motherboard, we've eliminated riser gone bad.
If after you build it outside the case and it's still crashing there's 2 possibilites left.
It's the 3080, or the SF750.
Those EVGA 3080 XC have 2, 8 pin connectors for power right?
So you want 2, single, 8 pin power cables plugged into that 3080 (not 1 and a splitter)
In the box of the SF750 you get 2 PCIE-e 8 pin cables with splitters on the end of each, are you using any of the cables with the splitter part plugged in to power the 3080?
If you are unsure, you can always post a pic to show us.
I can also see custom cables being used here, use the cables that came with the SF750 for any futher testing.
Especially with the 3080, they are hot running power hungry things. If you've bought and are using custom (cheap chinese) PCI-e cables that just aren't up to the power draw of a 3080, it's a safe bet this isn't helping you either.
The SF750 should still be good at 3 years old.
Test and report back
