No video input or output bad video card?

??????????
Maybe Windows problem. Hard to tell better description needed!

i have similar problems - last night was using the pc, dual monitor setup when bam screen goes black. Rebooted - i can hear the HDD working, but on my monitor it says "No Video Input" so i can't see POST - i hear the windows chime turn on, my keyboard caps lock can be toggled but no display - rebooting did not work, same as above


i've reseated ram, components, tried video card on another pc - worked - tried monitor with another pc - worked
disconnected all power except for boot drive, video and normal motherboard connectors

reset cmos, remove battery,

same effect- i know it is booting, ram test with mobo elicits the right number of beeps
scoured the web for answers, it turns out this seems to be a common problem but no common solution -
only thing i haven't tried is replacing ram

so posting it here in case some of ya might have an idea or two to check out

my system core i7-920, 6GB RAM, ATI4850, Win 7 64 home premium, 400W power supply