fans on, no video, no beeps

I have a computer with a SOYO Fire Dragon mobo and 1.8 P4. It has been working for a long time.

When I power it on, the cpu and case fans work. Hard disks and cdrom drives have power. There is no video and no beeps.

When I take the memory out, there are no beeps. The psu and video card work in another computer.

Ideas?