ATI Radeon HD 4850 not booting?

Hello everyone, I have read some other posts where ppl had problems with this card. The solutions, don't seem to apply to me so I am going to list my specs and problem to see if there are any other ideas.
I installed the above card today and my system boots, i hear the beep from the bios loading and my monitor actually wakes (power light goes blue denoting signal/power detected)...but that is all. the monitor actually detects no signal. I HAVE CONNECTED THE 6PIN TO THE CARD, lol. I have tried both outputs on the card. my onboard graphics are disabled so I assume the board has detected the graphics card. The fan is spinning and there are no lights blinking on the card. Any thoughts?

System specs:
Gigabyte MA78LM-S2H MOBO
Windows 7Pro x64 OEM
AMD Phenom 9850 Quad-Core 2.51Ghz
OCZ Platinum 4GB 1066
ATI Radeon HD 4850
Sound Card Onboard
Monitor(s) Displays Debranded 20" HD LCD

PSU 500W included with Apevia case
Cooling PSU fan w/copper heatpipes; 2 Case fans (5" side; 4"rear)
Hard Drives WD Caviar Black 650GB (running OS) WD Caviar Blue 1TB WD OE 500GB

Does the onboard video work? Pull the 4850 out and connect to the onboard video. If it works. power off, place the 4850 back in w/ the power. Boot up again, with the monitor still connected to the onboard, go into the BIOS and change the primary video to PCIe. Save and shut down. Change the monitor to the 4850 and power up... What happens?

yes that is my MOBO

I have the monitor attached to the onboard video now. I have picture, but it asked me to do a start up restore. I will look at the hardware when it reboots. I still have the 4850 installed.

I have output from the 4850! I wonder what the heck that was all about?????? I am going to shut down now and attach devices to the psu one at a time. If it is the psu what will happen, same thing? just no output?

***just lost picuture, monitor went to sleep, pc was still running?????? rebooted (hard boot) and monitor is back up but wasn't up during the post screen. Monitor didn't come back up until logon screen.***

I am thinking psu as well now. one thing however....why would i not have an image during the post screen? I want to go into the bios but I can't see anything prior to the windows logon screen.

that got it! I haven't hooked up the HDD's yet...gonna replace psu. thanks a lot!