Hello Gentlemen, and my warmest welcome to the forum to you Skuwulfe,
I have been away for a few months, and so most of you won't know me personally. However, in reading through this thread, it seems as if everyone is pulling our poor new member in too many directions.
I think that the best course of action is to take this one thing at a time, and not get side tracked.
OK, now Skuwulfe, when you purchased the PC, was it an AS IS sale, with no hope of recovery if it turns out that the original owner did in fact muck about in the interior? If not, I would definitely direct you to contact the AAFES store, and ask if any of their techs in fact looked at the PC prior to reselling it, or if they would be able to do a basic diagnostic with their own power supply, or to verify that the previous owner didn't try to "fix it".
Next, I would see if another power supply will work, a 250 will be fine to simply see if the PC can recieve power. You will be able to tell by the light turning on.
After you have done that, post back when you have some time to spend back and forth, and we can walk you through some basic diagnostics to see if the PC can power up.
Looking forward to your reply,
TTFN
LGW