I dont think it's the GeForce 8800 GTX graphics card, I tried another card and still, blackness. The LEDs on the mobo are the only thing that indicates anything is happening, it cycles through some numbers and ends with "FF". The cable and monitor are good. What else can I do?
Ha! I had that exact problem with my Asus 650i SLI motherboard. Plug your monitor cable into the other connector on your video card. I had 2 8800's as well, in SLI. That means there are 4 possible DVI ports, and any money says you have picked the wrong one. Just unplug your DVI cable, and try another port until the monitor comes on. Make sure you give each port 15 seconds or so to realize there is now an LCD connected to it.