No Fans, No Post, Help Please

Relatively new to the pc building game, and having a hell of a time with this. Green light comes on on the motherboard, fairly sure all my connections are good. I've removed everything and tried from scratch. Green light on the mobo comes on when i turn on the PSU switch, but when i try to flip the front switch to turn it on (and i'm sure its plugged in correctly), nothing happens. No fans spin, not even for a second.

As far as I can tell, its not a short, I can't get the screws to go all the way down to touch the motherboard but they're in pretty damn tight.

Components:
ASUS P5Q Pro LGA 775 Intel P45 ATX Intel Motherboard
Intel Core 2 Duo E8400 Wolfdale 3.0GHz LGA 775 65W Dual-Core Processor Model BX80570E8400
CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
mushkin 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model 996587 - Retail

I've even tried booting with either one at a time or both of the RAM sticks, so I don't think its the RAM...help is much appreciated.

What do you mean by "I can't get the screws to go all the way down to touch the motherboard but they're in pretty damn tight."? Unless you aren't using the screws that came with the case, there's something wrong. The screws should be short enough to go all the way down. Does the system power up outside of the case?

ASUS will say anything to stop you from calling customer support.

You have most probably mounted it wrong. If it hasnt burnt out yet. Take it out of the case and start the board with only the bare necessities (CPU+RAM). If it doesnt post. Hookup the PC-Speaker and remove a component at a time and listen for beep codes. The definition of these codes will be at the end of the motherboard manual.

no its mounted on the brass stands. i'm fairly confident that its mounted correctly. what i mean is that the screws don't go all the way down into the brass stands and squeeze the motherboard in between it and the stand. if that makes sense. there's just the tiny bit of wiggle room. anyway, i dont think thats the issue nor do I think the motherboard is fried. ill try taking it out of the case and running it there.

If the screws dont go all the way in you used the wrong screws.

Yup like Kamal, said double check the 20/24 power and the 4/8 power.