Dead PCI-E Slot?

[JT8101997]

I just bought a second 980ti and eager to get it running in my system, but my pc wont detect it. I have an X99 Deluxe motherboard and the first card is in the first slot and the second is in the fourth slot (distance of 1-3 sli setup) just enough for another card to sit in between the two. I tried it in the 2nd slot and it detected, so it's not a problem with the card. I also tried a 980 in the fourth slot and still nothing. Although i tried a sound card in the 4th slot and it detected it? I don't know what to do now. I've had the board for around maybe 9 months now so idk if i can rma it or if theres any way i can try to fix this? Save me internet

[Interfectorem]

Consult your motherboard manual. There may be certain PCI-E slot configurations that do not work.

[JT8101997]

Consult your motherboard manual. There may be certain PCI-E slot configurations that do not work.

Just checked. It actually recommends using this configuration.

[Spev]

I don't know much about SLI configs but maybe I'm missing something here. Have you checked to ensure that the card is functional? Have you taken out the one you're using now (in the current slot for just the one card) & put in the new card to ensure it's functional? I also see you checked the 4th slot with a sound card which worked, did you check the 3rd slot with the sound card? That is the one the manual recommends for the setup you said, but I didn't see any information about your troubleshooting that slot. Maybe try connecting your sound card to that slot & see if the slot is working, and check if the new GPU is working fine in the current slot you are using for just your one card. If it's the exact same card you should have all the drivers installed so swapping in the new card should just load up like normal I would assume.