On my Old (HP)Compaq S4000Nx the green power light comes on and the fan howls like a banshee but there is no monitor signal/no boot screen/no BSOD. Boat Anchor time?. The HDD amber light comes on for a second or two then goes out. HP dated it to 2003 so it's no great loss but I might give it another try.
OS is WinXp . There is NO Signal at all to the monitor(s), tried 3 different units. Cannot boot from CD or Floppy, (have tried both) Will not boot from Correct HP Recovery Disc set either. Can't get the BSOD or the Compaq Boot screen. Will not boot from the 'magic bullet' fix-all-your-Windows-problems-with-one easy-program-disc either. Power light comes on, Disc Activity light flashes on once for .5 seconds, no beep at all, just the CPU fan kicking into warpspeed