So I bought all of the parts to build a new pc, consists of:

Intel Core 2 Duo E4300 Allendale 1.8GHz LGA 775 Processor.
OCZ GameXStream OCZ700GXSSLI ATX12V 700W Power Supply.
EVGA 122-CK-NF63-TR LGA 775 NVIDIA nForce 680i SLI ATX Intel Motherboard.
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory (four sticks totaling 4g ram).
EVGA 256-P2-N625-AR GeForce 7900GS 256MB 256-bit GDDR3 PCI Express x16
HDCP Ready SLI Supported Video Card.

This is the first computer I've put together.

I've a fair amount of knowledge, enough to set up this pc, at least so I thought.

I've it all in my case, power to the processor, power to motherboard, hardrive connected, cd rom drive connected, graphics card connected. Power and data cables to everything.

Came down to the headers, I've power switch connected, I've reset switch connected. The HDD Led is connected, but the Pwr Led is not connected because it is three pronged or so. I didn't think that mattered to start the computer up anyway.

So I'm confused here, and asking for some help please, as to why my system won't boot up, it starts up for one second then shuts down.

I found out my problem was the risers, I had way too many put on and it was touching the motherboard, which explains why it came on and shut off like a second later.

Now I have the right risers connected correctly and only using which ones I need, it comes on, fans all spinning and on the led error it just says -- which means no error I do believe, but I've connected a video card and seem to be getting no connection through my monitor the screen remains blank/black.

So have I fried my motherboard?