Computer wont boot - GPU fan spins for a second then nothing else happens.

[SeanOHalloran]

Can anybody help me with this problem I am having. Just upgraded my case and have everything set up the way it should be. I can see the lights on my motherboard and also my GPU but when I power on the machine I can see the GPU fan spin only for a split second then nothing else happens. Any ideas what could be wrong??

 

[clutchc]

System specs?