Well, I'm no expert, and I wouldn't wrote me perfectly, but from what I'm seeing, your set up looks like it might not have enough juice from your Psh to power everything. I would personally try getting it to boot using on board graphics and pull off my video card. Is say this would be a very quick and easy test.
If you monitor doesn't support hdmi, just plug it into a tv with hdmi in and see if it will do anything different.
Again, I'm no expert, just stating what I'm seeing.