Need help troubleshooting

This is not my first time building computers, this issue is a first for me:

My issue is I turn on my newly built machine and nothing is displayed on the monitor, but to boot I cannot get the DVD drive to work for me either.

The power supply I have is a 500W See Apevia:
http://biz.tigerdirect.com/applica [...] CatId=1079

The DVD drive is a Sony NEC Optiarc:
http://biz.tigerdirect.com/applica [...] &CatId=480

The graphics card is a PNY Nvidea 8800GT:
http://biz.tigerdirect.com/applica [...] 08800%20gt

When the machine starts up, all fans are go, all lights are go, this includes the graphics card, but the DVD drive is completely unresponsive.
I've swapped out multiple DVD drives and tried using separate power inputs coming from the power supply, and still no response.

As for the display, I see the graphics card is running, all cables are connected, DVI, and still no response.

I am not sure what the problem could be at this point, any trouble shooting would be greatly appreciated.

Thank you.

Back story: I'm opening a LAN center and I have 20 computers to build, I've built and tested one computer which works great, which I'm posting this thread from right now. I am using a different DVD unit and a different power supply, all else is the same.

I don't believe the DVD player is DOA for the fact that Ive swapped it out with another one of the 20 or so I have and it also did not work, of course there is always the possibility that both the DVD drives I tested were busted.

As for the Apevia, I've heard and read nothing but great reviews when I bought it, this is the first negative review I've heard. = /

Ok, nevermind, I've discovered the problem, and as usual it was just a case of me doing something stupid.

I didn't attach the 4 prong power cable to the mother board = P

Any ways thanks for your help.