Dover ENM3308021 Power Supply Not Working

I have a Dover ENM3308021 power supply that is not working, or at least that's what I've been told. A customer gave the overly helpful description of it isn't working. When I power it on, the fan and LED's turn on and I get voltage on the pinouts. I matched the voltage (not under a load) to that of a working power supply of the same model. I'm a little out of my normal scope of practice here and could use some suggestions on what to test (and how to test) to see if I can determine the components that are bad. I solder well, so fixing it shouldn't be difficult, it's just a matter of finding what to replace. Any suggestions are helpful!