My first build... I plugged it in only to find I have no video. HDD spinning, all fans on (including heatsink), everything seems to be fine...
So I concluded it must be an issue with the auxilary cables to the video card. Unfortunately, my manual is not specific for the model (it is a Zotac GTX 275). It only says to plug in as many as there are. After looking all over the card, I only found a small 2 pin slot, which did not fit the plug on my mobo (I believe it said SDIF0 or something like that, mobo manual said this is normal to need to plug video cards here). However, there was an enclosed adapter which allowed me to connect that plug, so I did so.
But, there are also 4 prong cables included with the video card, and I feel like I might be missing something. There is a note on the GPU itself which says to plug "both" auxillary cables in or it may not work, I just assumed this meant the 2 pronged doodad. But, it seems I must be missing one. I can post photos tommorow, but right now I need to crash. Hoping somebody has installed this video card and can give some guidance.
The SPDIF is just a external connection that is necessary to have HDMI output from your computer, this is not the case though, I have had cards w/ the SPDIF but it's not necessary in order for the video card to function properly.
Try using your computer w/o the video card installed and simply connect your monitor to the I/O of the motherboard and see if you problem persists. I have a feeling it's going to go away, if that's the case you either have a problem w/ your video card, not enough amperage supplied to the card, or maybe a hardware issue w/ the PCIe slot (rare).
Also what is the rated amperage of your 12v rails, the ones you use to power your video card? If you don't have the necessary voltage for that card it will not function properly. You will find this spec on the side of your Power Supply (PSU). It will say how much amps are supplied to each cable and how much combined amps are supplied to the 12v rails in total.