"Originally, I booted up, got the F1, and F2 messages. Did the set up of boot sequence, and was fine.
Rebooted with an add-in HD that was a Samsung 120GB as secondary HD, But OS did not like it so I removed.
I shut down for the day.
In the process of getting a driver for the sound card.
Re-booting, and got the Black Screen."

I was using the computer for at least 5 DAYS.

while updating software, and installing USB card, Sata card, and was in process of installing the sound card, when it went Black Screen.

I have a friend who has a GeForce 8400GS card in computer.
Negotiating a "borrow"to try deal. with very fast turn-a-round.

I did try winxp pro and Home OS disks. but as get blank black screen,
no loading from DVD/CD.

I will remove all cards, and re-try, will keep posting results.
Thank you.