|Update and new issue with this computer.|
We were able to find the original CPU but it was damaged, thus it was unusable. It was a Celeron D 2.53 GHz/256/533 SL7C5 Malay. We replaced it with an identical one.
When I booted it up, it booted fine, loading all the way up to and through the password login. Then within a minute, the system went off. Now when it is booted up, the CPU and case fans spin, but the POST and OS do not load. Likewise, there is no system light illuminated on the front of the case like normal.
My thinking is that the board itself is suspect, but I want to be sure.