Performed diagnostic/evaluation on older Goodman system. Upon arrival, the homeowner said the unit started back working after about an hour of it not turning on. After performing evaluation really couldn’t find anything definitive to determine why the unit shut off. I didn’t notice the Duke energy, module on the system could actually kill power to the unit due to the grid being overloaded. Instead of charging the homeowner the diagnostic fee I signed him up for a maintenance plan. The homeowner agreed and advise him to call the office to get his first maintenance scheduled.