Question Computer ran fine, upgraded with a used GPU (Gigabyte GTX 1080 Ti) and PSU (EVGA 750W) from my friend who shipped them; having issues now

[ztpurcell]

This computer had a 1650 Super and 750W PSU before, and I think the PSU was starting to have issues so that's why I replaced both. He was just using his 1080 Ti and power supply a couple months ago before getting new stuff, but they're not acting right in my machine now.

The only issue with the PSU is minor-ish; the computer won't turn on when I have something plugged into the second SATA slot on the PSU. It immediately shorts, and I can't get all the SATA needs satisfied with just one cable.

For the GPU, the fans run, but it won't output display no matter what I do. I've tried with the cables he was using before and I've tried with new cables I had in my spares. The LED's above the connectors on the GPU haven't lit up once. The computer works totally fine when run from motherboard graphics, and the device manager detects an unknown PCI device but I can't force it to install GTX 1080 Ti drivers and Nvidia says there's no Nvidia GPU in the system so it won't try to install anything itself.

I've unplugged and replugged all of the cables at this point multiple times (CPU, motherboard, VGA, etc). I didn't even touch the CPU, RAM, or anything else in the computer beyond the power supply and GPU stuff. What are some possible things I'm missing? Or is it also relatively believable that they experienced some damage while shipping and one or both are now toast?

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

Replacement PSU: make, model, wattage, age, condition (new, refurbished, used)?

Did you use only the cables that came with the replacement PSU?

 

[Joseph_138]

Don't understand why you would consider a 1080 Ti as an upgrade in 2025. There is no longer a justification for using a Pascal card this far out. Even the Titan XP is weak against modern games. Return it to your friend, and get something newer.