when i built the pc put a hd4350 ati in from the start, thought it had onboard graphics but just had a look no socket on the computer to plug the monitor in only hdmi,dvi,dvga sockets were on the graphics card so that option looks a dead end.
updated the ATI diver yesterday but had restarted ok a few times since then ok, not getting any bleeps but all seems working ok, tried booting with windows dvd no luck on that. re seated everything as well.
all fans working, dvd tray open ok it is as if the monitor is not plugged in. but my own mointor with hdmi and another monitor on dvi both fail to show.
if it is the new driver cannot boot into anything to run backup image or reload windows.
just a thought.....do you have the extra 4 pin power lead for the cpu ???
i had a problem with this once, did not seat properly .
stopped the pc dead ,but all fans and lights worked....worth a try !