Very strange that you are getting a good post beep and that the onboard display has failed. Does it give the same beep with the PCI card removed ?
There ARE a few old bios systems that beep one short for a problem. Rare but they are out there. A Bigalow T/S book that I have has 1short as meaning "System RAM Refresh Failure. The programmable Interrupt timer or Prog. Int. controller has probably failed. Replace the mobo." for AMI Beep Codes.
Also, for AST Beep Codes, 1 short means "CPU Register Test Failure, replace mobo or cpu" No personal experience, but that is what this books lists.
If that's not the case and 1 short means good, and your determination that the onboard graphics are shot, then the POST seems to be recognizing that the PCI card is installed and OK, so I guess the bios setting isn't letting it take over for the failed onboard graphics.
Is there any difference in booting up as far as the beep code that sounds when you remove the PCI card ?
Have you tried all the PCI slots ? Sometimes changing the postion will make a card work.
Why did you have a card installed when you were using the onboard graphics ? Since you said this is an old computer, it probably doesn't have an automatic onboard disconnect when a graphics card is installed like some newer systems now have.
W2K had alot of driver compatibility issues while running dual monitors. Many times they would work seperately but not together.
Also very weird that you're getting a splash screen, but not a boot display. I can't even think of a theory for that one.
And you're saying that you did an repair install without seeing a display ?
One last suggestion. I have seen bad ram cause a blank display with nothing wrong with the graphics card, so check your RAM in another machine if possible, or if there is more than one stick installed, try one at a time. This could be a likely theory using onboard graphics which use shared memory.
Also, could the keyboard's delete key be inop ?
Maybe verify that it works on another computer.
All else fails, you can get a W2K tower these days for about $40 or $50. At some point you have to ask what your time is worth trying to fix.
Hope to hear from you again.
Good luck