Getting ready to head South next week. After wintering motor home, left it plugged in and with all slides closed. When I went out today and opened the door, I could see microwave light on but nothin...
Try turning off 120 volt circuit breakers, applying light pressure toward off. Then turn on main breaker if equipped. The turn on branch breakers one at a time. Converter if working should apply 12 volt DC power to the system. Your batteries could be good but need charging as it sounds like converter is not operating.