After occasionally failing to launch the cooking cycle, while still displaying numbers, my microwave has gone completely dark. I suspect my control board needs to be replaced. But I can't see how to access it. Videos for other units show open screws you can pull out. I don't see how I can access it without opening the entire housing, which has screws requiring a special tip which only the repairmen have. Maybe the intent is to keep amateurs out of this area.