The circuit board stores 100 fault codes. As long as you do not turn off MAIN POWER the memory holds. If you turn off toggle switch...ice--off--water the memory also holds. If they are still there count the LED flashes to guide you to possible problem. Code bible is on inside door sticker. If all is erased cycle the unit and see what happens. Time out complete cycles to get an idea if production is within normal specs. Manitowoc will allow 3 re-starts before locking out entire unit. Also ask questions of the staff. Try and get some idea when unit stops making ice. Does it fill overnight but stops uring day? You need to filter what you hear since you rarely get the truth but sometimes the customer tells the truth while covering up with a lie. Manitowoc tech support is 800-545-5720. Great tech help but they ask basic questions you need answers to. If you don't have a set of tech books, find them. They usually get you to where you want to be. Good luck. If you write back, try to have specific info of what it is or isn't doing and patterns. We can't help if we don't know.