Microwave displays E09 and beeps; clock and basic functions may still work but cooking is disabled.

Safety first: Always unplug the microwave before inspecting the cord or internal components.

User-level checks:

• 1. Test outlet: Plug the microwave into a different, properly grounded outlet on a dedicated circuit. Avoid using extension cords or power strips.
• 2. Check for other heavy loads: Ensure no high-wattage appliances (toaster, kettle, heater) are running on the same circuit, which can cause voltage drops.
• 3. Inspect power cord: Look for cuts, kinks, or burn marks on the cord. If damaged, discontinue use until replaced.

Advanced checks:

• 4. Measure line voltage: Using a multimeter, verify that the outlet provides stable voltage within the specified range (typically 220–240V or 110–120V depending on region).
• 5. Inspect line filter / noise suppression board: Inside the unit, check the line filter board and connections for burns or loose terminals.
• 6. Replace control board: If supply voltage is correct but E09 persists, the internal power supply on the main control board may be faulty and require replacement.