I bought a used Avanti mini fridge that had been converted to a kegerator. So far as I could tell, it had been working for its original owner. I got it home, plugged it in overnight to let it cool, and woke up this morning to a warm fridge. The compressor seems to be running, there's no clicking or anything to indicate it's turning off, and it seems to me (other than its lack of coolness) to be running like a normal fridge.

I know nothing about fridge repair. I've been searching around trying to find information, but with so many models of fridges I'm afraid I'll get information that's not relevant to this model. I got the fridge pretty cheap considering it's been converted to a kegerator. (A new, already built kegerator will run $500-$1000 easily.) I'd like to see if I can fix it myself before either (a) taking it to a repair shop or (b) getting another mini fridge and saving the kegerator conversion parts from this one.

I've attached images that may or may not help. Like I said, I'm totally new at this. If I need to provide any other information I'd be happy to. Thanks for any help!