Bad motherboard?

I was installing a new cooling fan for my processor the other day, and after finishing the computer would not even post I opened it up to see what code it was stuck on, and saw that no codes were being posted at all. the fans turn on, motherboard lights turn on, but the power button LED on the motherboard is not lit up, and it will not shut down using the power button (only turn on) I'm wondering if it's a bad motherboard or bad CPU. The graphics card fan does not run at all, but the PSU fan does function. I've taken the motherboard out of the case and run it with no success. I've taken out all memory sticks, and still get no post codes, no beeps, no nothing. Any ideas if it's a bad motherboard or bad CPU?

Specs:

EVGA x58 3-way SLI for Intel Core i7
Intel Core i7 processor @2.66 GHz
EVGA graphics card, triple channel ram, Dark Knight cooler.

Yea it had a backplate, but I removed the backplate and tried the old processor fan, but that didn't work either. If i can do something to fix it that'd be great, but I'd also like to make sure that ordering a new motherboard is the best bet (and that it's not a bad CPU instead)

Thanks for any replies/suggestions

EDIT: It was the dark knight cooler if that helps any.

power cable definitely fully inserted. What are the odds it's my CPU? I figured it's my motherboard as the power switch on the motherboard does not shut off the computer, i have to manually shut it off by switching off the PSU

Thanks for the reply =)

I thought about that, not sure if I overtightened it or not. I did not hear any crack or the sort. I'm guessing there's no way to check for a bad CPU without an extra one to test?

Thanks

Gottcha. I thought about trying to buy a cheap processor, but my motherboard only holds I7's..so there is no cheap CPU to test =P I just decided to order another motherboard, and if it's the CPU return the motherboard and get a new CPU.

Thanks for your help!