boots up now.. but new problem and question

[geo3tech]

Hi guys. This is a new rig that I just received today.

GIGABYTE GA-MA790X-UD4P AM3/AM2+/AM2 AMD 790X ATX AMD Motherboard - Retail

CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 ... - Retail

AMD Phenom II X3 720 2.8GHz Socket AM3 95W Triple-Core Black Processor Model HDZ720WFGIBOX - Retail

SAPPHIRE 100259L Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail

G.SKILL PI Black 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL4D-4GBPI-B - Retail


Problem is, I get no start up beep from my motherboard and also I am getting no post screen on my monitor. I have gone through the ""New build won't boot" checklist sticky post and currently testing in the breadboarding way. I am guessing something is faulty and I think it's the Motherboard, but I am not sure. Which piece would i have to RMA ? motherboard? psu?

 

[Kill@dor]

Are you sure you PSU is on? LOL

Did you load windows yet? Make sure everything is plugged in right?

 

[geo3tech]

Yes. The fans on the graphic card and the CPU all run, I see the lights on the graphic card too. And no, i havn't yet connected a hard drive yet since I'm still in the breadboarding stage. Can't install windows yet if i can't see anything on the screen or go into bios to see what's up.

 

[Kill@dor]

Plug the hard drive in then...without loading windows...but your board may still need to see it....

 

[Kill@dor]

Make sure your RAM is sitting nice and tight...

 

[geo3tech]

I tried plugging in the hard drive, and nothing is still coming up. My monitor is blinking.

What is weird though, I plugged out the 8pin cpu power cable and plugged in a 4pin cpu power cable instead into it. The Screen actually came up with the post. I got all excited and restarted the motherboard so that I can go into the bios, but then ...... blank screen. Monitor is still blinking as if it never saw anything. Could there be anything that could cause this?

 

[geo3tech]

Update: I placed my video card into the PCIE x 8 slot instead of the PCIE x16 slot and it booted up fine. I am also using a 4pin instead of a 8pin for the cpu power. Is this because of a defect in the PCIE x 16slot or do I have to enable something?

And if it does end up the x16 slot is defected, would it effect my game performance a lot by just keeping it in the PCIE x 8 slot?