When I use a PCI-e video card in PC I don't get a signal to my monitor. I had a 680i before and I thought that the slots were bad so I RMA'd it to EVGA and got a 780i as a replacement. But even with the brand new board I am still having the same problem. It's some compatibility issue that I can't figure out, because if I stick a PCI card into one the the PCI slots it works fine. It's not a bad video card or monitor as I have tried several. Does anyone have an ideas on why the PCI slots would work fine and all the PCI-e slots don't give signals? I also tried a new power supply and got the same so I don't think it's that either. I'm really stumped on what could even be the problem and I was hoping for some ideas from anyone out there, thanks.
It honestly sounds like what happens if you still have your onboard graphics adapter enabled -- video cards won't work, but any other kind of card will. Since it's a new board and you didn't mention messing with the BIOS yet, it seems fairly likely that the onboard graphics are still on.
And since video cards are usually the only thing that goes in a PCIe x16 slot and everything else goes in a PCI or PCIe x1 slot, I wonder if that's confusing the real issue?
What kind of cards are you sticking in the PCI slots that are working? Another graphics card, or something else? If it's anything other than another graphics card, see if the onboard graphics is still active in your BIOS, and if so, disable it and see if that solves the problem.