I've decided to put together a credible gaming PC which consists of:

Intel Quad Core Kentsfield 2.4Ghz Q6600 CPU
XFX nForce 680i LT SLI Socket 775 Motherboard
EVGA 640-P2-N821-AR GeForce 8800GTS 640MB 320-bit GDDR3 PCI Express x16 HDCP Video Card
Kingston 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory
Antec True Power Trio TP3-650 ATX12V 650W Power Supply with Three 12V Rails
SAMSUNG SpinPoint T Series HD501LJ 500GB 7200 RPM SATA 3.0Gb/s Hard Drive
SAMSUNG 18X DVD±R DVD Burner with LightScribe and Software Black IDE Model SH-S182M/BEBM
Thermaltake CL-P0401 110mm Full-Range Fan CPU Cooler
Antec Nine Hundred Black Steel ATX Mid Tower Computer Case
SAMSUNG 906BW Black 19" 2 ms (GTG) DVI Widescreen LCD Monitor

I am having a few issues. One is that my GPU is not sending any signal to my monitor. It is connected by a DVI cable that I know works; I've taken a PCI card that has a VGA connection and inserted to find my monitor will display a picture. I have also tried changing the port that it is in to see if that changes anything and nothing differed. My other problem is that my computer upon start up will flash up to the POST screen and then power off, this leaves my computer on for about 15 secs before it turns off. I've checked the connections, then tried minimizing the load, and I switched the channels that the memory was sitting in. I'd like to note that upon startup everything seems to be getting power, all of my eight fans turn on, all LEDs illuminate before everything turns off. If anyone has any suggestions please let me know. Thanks.

Just double checking, you do have the power plugged into the PCI-Express vid. card, correct? You said you see the post screen. Do you hear the POST beep? The board could possibly be shorting out on the frame. The best thing to do is put the board on the bench with the minimum stuff hooked up and then add things one at a time
Mark

Oh, my friend had a similar problem with his computer. His new computer build would turn off after a few seconds of being on. It was that his processor was overheating. He took the thermal paste off and put on some new. This made his processor temp go from 70 degree's celsius down to 29 celsius when he turned it on.

My wife's new system would behave the same way - turned out the heatsink fasteners weren't on securely (darned incompetent techs! Whoops! It was me!

But, I'm concerned that you can't get a signal from your video card, so I'd also check the things that garmanma suggested

Thanks Usama,

I reinstalled my fan and switched my memory and everything worked fine. I know I said in my intitail claim that "I" switched it but it was a misunderstanding between my building parnter and I. But nevertheless everything works great. Thanks again.