We have about a hundred of the aforementioned computers in our library system, and yesterday I came across a curious problem that I've never seen before.
When I plug the DA-2 power adapter into only the wall, the adapter light turns amber - so far so good. When I plug the 8-pin connector into any other* of our machines, and then hit the power button on the machine, the light turns green, and the computer starts. This is expected behavior.
BUT when I plug any* power adapter into this specific Optiplex, the light on the adapter immediately goes out. *poof* (though without an actual noise. It just goes away silently)
It comes back when I unplug and replug the adapter to the wall, but only if I've unplugged it from the computer.
Obviously, the computer does not turn on.
Thoughts? I'm guessing a short, but I'd love to get this machine working...