Black screen on startup

after formatting, the PC doesn't boot anymore. All I get is a black screen, not even the BIOS shows up. Tried removing the GPU so it loads onboard graphics instead.... same thing. Any suggestions before I bring this bugger in for repairs? :confused

Oh it's running XP SP2.

 

Swap in a known good PSU and see what happens. Are there any beeps? Can you see or hear any activity (fans or drives) when you first power up?

Why did you reformat in the first place? Note that is always a last resort option because so much is lost, including all the drivers, updates, and user settings. Also, the cause of the original problem cannot then be determined thus the user learns nothing to prevent recurrence.

Did the hardware work fine before you reformatted?