Dead Ultra X-connect 500W ATX PSU?

I recently acquired this PSU from a friend, as it has been sitting in his shed for a few years. I plugged it in to an old computer to see if it works and the thing is dead. Now, I don't have much knowledge when it comes to circuitry or PSUs, nor do I have the parts that I would need in order to fix it. So, what do you think my best course of action is? If I took it to a small shop, would they be able to fix it? What kind of cost am I looking at for it to be fixed? Or am I better off just buying a new PSU? Is there really anything that I can do with this PSU? I don't really want to just get rid of it, seeing as how it's a discontinued model, and fairly expensive, and all.