He doesn't have a GPU. Are you gentlemen sure that it will even post without video? I had an old HP motherboard that wouldn't post without video card. It would max all the fans for a few seconds then it would turn itself off.
I just think you should get a GPU, any GPU, before you start RMAing parts.
You hit something here and I had to look at his mobo - you're most likely correct as I see the mobo does not have any onboard video!
When the OP said that he didn't have a GPU I was thinking along the lines that he didn't get a dedicated GPU as his upgrade, but that's not the scenario here.
OP - get a GPU that will help.