Hey there.
I just built a new rig with a GA-Z87-HD3, i5-4670k processor. The new machine posts, works perfectly ... but will not display output to the monitor in any fashion when a GPU (Asus GTX560Ti) is installed in the PCI-E slot, not even the motherboard's boot-up splash screen. My monitor just gets no signal. I managed to install an OS and get into the machine by removing the GPU, and if I set the BIOS settings to have the IGPU as the primary video output instead of the PCI-E slot, then it works. But it won't boot-up (or at least display any video) with the GPU installed.
I have made sure that the issue is not with the GPU, as I have tested it in other machines and it works fine. I have also tried other GPUs with this motherboard, and they do not work either. I downloaded the latest drivers for the GPU, and also flashed my BIOS to the latest version (F6). None of these efforts have had any effect.
Can you suggest anything I can try to get the video output working with a GPU please? Or do I have to assume I've been sent a faulty motherboard?