New system ran great, then lost video

I built the system in my sig about a week ago (all parts from newegg) and it ran great. It started up first boot, installed Win 7 64bit without a hitch, played a few games (FSX & LoTRO) on ultra-high with good temps for several days... then one morning after leaving it on overnight (it had previously been going to sleep after an hour as told) it was still on in the morning, but wouldn't project a picture. So i hit the reset button and it gave the usual signs of rebooting but still refused to display post or anything else.
I have since breadboarded the system with just the MB, CPU, GPU, PSU and RAM. It gives zero beeps with everything installed.
Putting either memory stick in slot 1 returns no beeps either. Removing both sticks of ram gives 3 beeps.
Removing the GPU (there's no integrated graphics on this board) returns zero beeps. I've tested the monitor and the HDMI cable.
All fans spin up like normal, the moving hd spins up and chews, everything seems to work... except the display. I reset the CMOS already too despite never entering the BIOS.
I'm going to get another el cheapo graphics card to rule out the radeon card. Any thoughts?