Most likely it has overheated, many times and that is what is frying the coils. Glad it had a happyish ending. When you see stuff like this you know they don't want to put money into it. Don't be afraid to tell someone a piece of equipment would cost more to repair than it is worth. I do it all the time with the box store $100 chainsaws and $50 string trimmers. Some folks do get frustrated when i tell them to fix the cheap string trimmer they left gas in will cost at least $75. At least an hour labor and a carb kit and fuel lines and filter.