Is there any chance for you to try the graphics card onto another system?
Try re-seat the processor. Also make sure that you have connected all the power connectors properly.
Basic test, remove everything from the system. Connect only processor and it's fan, motherboard and power supply.
Start the system, you should get three beeps.
If you do not get three beeps, then there could be something wrong either with the motherboard or even the processor.
If theis happens, try to test the processor onto another motherboard or test another processor onto the motherboard, this will be the only way you will know which one is causing the issue.
If you get the three beeps, then power off the system, add 1 module of memory, graphics card, keyboard and monitor and start the system, you should be able to get video. If everything works fine, then add one component one by one and it should work fine now.
Else, you may try to do a bios recovery:
Download the bios from the following link:http://downloadcenter.intel.com/license_agr.aspx?url=/10130/eng/P25-0077.BIO&ProductID=950&agr=Y&sType=&PrdMap=&DwnldId=10130&strOSs=38&OSFullName=OS%20Independent&lang=eng
Read the instructions on this link: http://downloadmirror.intel.com/10130/ENG/BIOS%20Update%20Readme.pdf
After bios update, everything should work fine, if still nothing, then there could be a problem with the board if you have managed to make sure all other components are working fine onto another system.
Let me know us know how it goes.