Thanks for the reply.
When you say it could not handle the light load, are you saying it is a faulty PSU or an incorrectly sized PSU for my build?
How interchangeable are old PSUs? I have a 9 year-old machine that this new one is going to replace that I could borrow for a bit if it would connect and not cause further damage. I'd rather not take that machine apart though, because I still have a need for it. I also have a machine that is even older than that (14 years?) that I could use.