So when I unplugged the stock HD Radeon 7770, I tried to plug in the gtx 480 and when I attached my monitor (Hanns-G 269 27") it would just say "monitor unconnected" and stay in power saving mode.
I have tried downloading the drivers for the gtx 480 and updating the ones for the 7770 but 7770 is already at newest driver, and the installer says that there are no nvidia cards attached to mobo and will not download.
I tried taking out all video cards, but the integrated graphics (it said it had them... ) were not "seen" by the monitor either.
I currently have a single six pin connector attached to the gtx 480, but there is also an eight pin connector right beside. Should I try to attach an eight pin connector there? I would try but my PSU does not seem to have come with any 8 pin connectors....
Of course you should attach the 8-pin. All PCI-E power sockets MUST be plugged in. That's why the GPU doesn't work- it's not getting enough power. And if the PSU doesn't have the power connectors required by the GPU, chances are- it's not powerful enough to run it.