Faulty Motherboard??

[blueagle78]

I ordered my stuffs from net and got everything today. I was excited as you would expect and start putting everything together. My excitement died when I tried switching on the PC but it won't come on. I checked all the connectors and even tried a different PSU from my old PC.
Then I tried my new PSU in my old PC. I only plugged in ATX and ATX12V cables on the old mobo and old PC came on.
But when I'm doing the same on the new PC its not working. New MOTO has 24PIN ATX connector and my PSU has got 24 PIN. While ATX12V has got 8 PINs and MOBO has 8 conntor for it.
Mobo is Gigabyte EP45T-UD3P
PSU is Corsair 400W.

Would you be able to suggest something before I decide to send the MOBO back?

[blueagle78]

Ok, I've got mobo working now. It seems it was short circuting inside the case so I took it out and it started working. But now I've got another issue!
Nothing's coming up on the screen. PSU fan is running and so are internal case fans and hard disk is spinning too. What could that be? Graphics card?
Another thing which worries me is the CPU fan, it starts when I switch on the PC but then stops. Is it coz processor doesn't need the fan yet or there's a problem? I didn't leave it running for too long to test this because the last thing I want to do is damage the processor.