Ordered 3 parts to fix 3 potential causes. When I removed the microwave from the built in cabinet and tried to take the back cover off, 2 of the screws required a special drive pattern to remove the screws. Only GE approved repair facilities have this special drive. I called a repair company. They were great. They came out the same day, installed 1 of the parts purchased and the microwave was repaired.
AppliancePartsPros responded to me several times, even on Sunday, about this problem. Great customer service!