If your microwave is sparking when there is nothing inside, it could indicate a few potential issues. Here are some possible reasons for sparking:
Residual Food or Grease: Even if you don't see any visible food particles, there may be some leftover food or grease splatters on the interior walls, ceiling, or floor of the microwave. These residues can cause sparking when the microwave is operated.
Damaged Waveguide Cover: Microwaves have a waveguide cover that protects the opening where the microwaves enter the cooking area. If this cover is damaged, it can cause sparks. Check for any signs of damage, such as cracks or burns, on the waveguide cover.
Metallic Objects: Metallic items should never be placed inside a microwave as they can cause sparks. Double-check that there are no small metal objects (e.g., aluminum foil, twist ties, or metal trim on containers) accidentally left inside the microwave.
Deteriorating Interior: Over time, the interior of the microwave may degrade, particularly the paint or coating on the walls. If the protective coating has worn off or become damaged, it can cause sparks.
Defective or Malfunctioning Components: In some cases, the sparking could be due to a malfunctioning component within the microwave, such as a faulty capacitor or diode. This requires professional inspection and repair.
It is crucial to address the issue promptly to avoid any safety hazards. If you continue experiencing sparking or if you are unsure about the cause, it is recommended to discontinue using the microwave and have it inspected or repaired by a qualified technician.