Flashing / sparking visible
- 1.Switch the microwave off at the mains power and remove the plug. 
- 2.Open the door. 
- 3.Check that there is no foil on the food and no metal objects inside the microwave. 
- 4.Ensure the container / dish that you are cooking food in is microwave safe. 
- 5.Check that the wave guide cover is not damaged or covered with food debris.