GPU not being detected.

[Sakiism]

I've recently turned on my old PC which I haven't used in a long time, and added a GPU. Unluckily for me, the GPU isn't being detected at all. Not in bios, Geforce experience didn't detect it etc.
I have tried
Blind faith.

Turning off and on.
Reinstalling drivers (It didn't recognize the device)

Changing the PCI-e ports  
Reseated the power cables 
Swapping it to PEG, then changing the ports and saving the settings. (Every time it reset to save it it would swap to auto) 
GPU:7700k i7
MOBO:Z270f gaming
PSU: TX850M
The only sign of life I have is the two lights being on, does this mean it's dead? 
(If it is, please tell me what GPU I should get for this that isn't being scalped to hell) 

[Sakiism]

1080TI, by the way.

[Bombastinator]

Older computer.  Are it’s various software bits up to date? Shouldn’t matter for a 1080ti.  That’s not a new card.  Might be for the bios and cmos and stuff on the mobo I guess. I’m not sure how old your machine is.

[Sakiism]

7 minutes ago, Bombastinator said:

Older computer.  Are it’s various software bits up to date? Shouldn’t matter for a 1080ti.  That’s not a new card.  Might be for the bios and cmos and stuff on the mobo I guess. I’m not sure how old your machine is.

3 years old. I couldn't use it for... reasons. It sat in a room for 2 years because of the reasons before, away from most things that would damage it. It booted just fine with the IGPU, so I'm assuming it's not the Cmos, and I updated the bios so it's not that. However in trying to update the bios for the GPU, it didn't detect it. Infact, no program detected it. Not even Bios. A driver updater said it had to update, so I'm assuming there's a singular trace but I have no idea why it isn't working. I've tried everything that I could think of up there, but I'm ready to try everything more to get a working gpu because of this crisis on hand.