XFX nforce SLI 790i ULTRA

[Cirion]

Hey!
Bought a new computer and put it together, consists of:
XFX nforce SLI 790i ULTRA
Asus Geforce 9800GX2
2GB (1x2) OCZ3P1600EB2GK 1.9V DDR3 Memory
Intel Core QUAD Processor
2xHarddrives

My problem is when I boot up the computer my screen is blank (no I have never got it working) and I get stuck at boot code 7F, if I press f1 I proceed to (while it counts other digits on the display) to FF and nothing more happens, screen still blank.

I have tried to replace my ram with a 1.5V ram stick of 1gb but its still the same.
What more should I try?

[XFX Tech]

The boards are set by default that you have a floppy installed. My guess is that you don't which is why you get 7F. It is stopping you because of the floppy error. When you press F1 it tells it to continue on and eventually the boards boots properly displaying FF. This shouldn't give you a problem getting display. What kind of power supply are you using? What is the color coming through your power connections on the GX2? Is it green or red? You do have a 6 and 8 pin connection, right? These should not be adapted. These should be native to the power supply.

[geforcer]

I know it's gonna sound stupid, but try switching the monitor cable to the other port on the video card.