[SOLVED] Help upgrading my dimension e521

My old Dell E521 used to be running an amd athlon 64, which I just replaced with a phenom II x4 945.

Both CPUs use the same socket, am2, and my PSU is more than capable of handling the newer card.

When I try and turn the thing on, everything seems to be fine. The power LED turns on, the fan turns on, and my monitor detects that the PC is turned on.

Despite this, no video is displayed. I've rebooted the thing several times, and I've gone through the process of resetting the BIOS settings.

Through all these attempts I haven't made any progress towards getting it to the boot menu. Is there anything I can do about it?
 
Solution
You go to Dell' support page, enter PC' service tag number, and go to Downloads. There should be BIOS section, with instructions how to update it, and release notes. Check release notes for new CPUs support.