Visible sparks or arcing inside the microwave cavity during cooking, often near the waveguide cover or metal objects.

Immediate action: Stop the microwave at once and unplug it.

User-level checks:

• Remove any metal objects, twist ties, or foil from inside the cavity.
• Inspect the waveguide cover (usually a small rectangular panel on the side or top interior) for burn marks, holes, or cracks.
• Clean the interior thoroughly with a mild detergent to remove grease and burnt food, especially around the waveguide cover.

If the waveguide cover is damaged:

• Do not operate the microwave without the cover in place.
• Order a Hoover-compatible mica waveguide cover and replace it following the user manual or have a technician fit it.

If cavity paint is damaged:

• Small chips can sometimes be touched up with microwave-safe cavity paint, but extensive damage requires professional assessment.