Apollo Microwave convection oven issue

Get a different/better unit and move on. Those Apollo units are cheap builder grade junk and fail all the time. They just cannot withstand the vibration and the bumps of RV travel. Dometic makes some good units or you can find a consumer grade unit from a household appliance store as a replacement. The Sharp "Carousel" line is seen in a large number of rental motorhomes and I can personally vouch that the unit is a real workhorse with very few failures experienced.