Maximum PC

I just bought a whole bunch of computer parts off of newegg and i put it together only to find that when I hooked up the monitor and turned it all on it gave me a no signal message. This is what I have in my system:

Antec Super Lan Boy
Gigabyte SLi Deluxe
Amd 4000+ OEM
Zalman Cu7700
2 EVGA 6800GT's
1Gb Corsair XMS 3200 Pro (the one with the led's)
OCZ Modstream 520W
2 Western Digital Raptors
NEC 16x Dual Layer DVD burner


I know its not the graphics cards or the monitor because I have tested both of those on other computers. I think the motherboard is defective but I'm not entirely sure.(It's been a while since I built a computer) I should be supplying more than enough power to it and the graphics cards both light up green as well as all of my case fans. Is my motherboard defective or am I just missing some small step?
Any help at all would be appreciated.
Thanks

Have you tried using just one video card in your system? If I remember correctly you have to set SLi mode in the bios or maybe a jumper on the mobo and you have to use a connector to connect the 2 cards. Could be wrong but its woth a shot. I would say check you settings if they are correct and it won;t work try just one card see if it will get a signal if so you know it is something to do with your SLi settings

This really belongs in the Free Clinic- hopefully a mod will see & move it so that you get more input.

GA-K8NXP-SLI nForce4 SLI chipset

Looking at the online version of your manual- page 6 of 88, the mobo diagram- I see an SLI switch between the cards. Page 18 of 88 explains setting up the SLI. Page 20 (Step 3) explains how to adjust the Bios for SLI.

Page 15 of 88- incorrect memory will cause system no boot. 1 module should be in DDR 2

You didn't list what power supply you are running.

Post back & let us know how you made out after checking these things.

Ok sorry about posting in the wrong forum.
I am using a Modstream 520W PSU and its supplying pwer just fine.
I have allready tried using one card two cards an X300SE and had the same problem.
I have allready tried setting the SLi switch but to no effect.
Also even if I have 2 DDR's in there it should at least give me an error message on the screen right?

You have to have the ram in the correct slots- if they are wrong it says -incorrect memory will cause system no boot.

If it were me, I would unplug everything, then start again. Are you sure your processor & HSF are seated properly? Also pull out the ram, use only 1 stick in the correct slot. Be sure all of the front power connectors are correct. It's pretty easy to hook these up wrong. If you hooked up the sound wires- disconnect them for now.

Are you able to see bios at all or do you get the no signal error? If so, something is not connected properly.

If the online manual is better than the one that came with the board, print out the main pages of it and follow them.

Are you getting any beeps at all?

Which slot is the correct slot for the ddr sticks?
And yes I'm fairly certain that I have the cpu/ fan and heatsink in.

The motherboard maker should have included a manual with the motherboard that identifies where all the items should be placed.