We went camping this weekend and were using our generator several times. We used it for air conditioning, microwave and blow dryer but never at same time and for periods of time from 30-45 minutes. As we turned in on for the night Cool down there was a small pop, generator engine shut down but made a constant buzzing sound and smell of smoke. I looked and the urethane around the circuit board was melted in one corner. I came home and tested all of the systems with shore power and everything works as normal. I can replace the circuit board pretty easy but concerned another issue caused this. Can a circuit board in urethane just go bad after 11 years in this manner or should I look for other causes. Already checked connections and for bare wires with no results.