The Official unofficial CPE 2000i Generator Thread

I just purchased a pair of used champion inverters from a guy and he Told me the one doesn't output Power anymore. Eventually I will be using the parallel kit. I basically got that one for free and paid for the one that runs good. He doesn't know why it doesn't put power to the plug anymore, the engine still runs great. I am taking it apart to see, any ideas on
what to test or look for? I was thinking the breaker switch might have tripped on him once and went for a crap. Any ideas please