Microwave shows E5 and stops mid-cycle, often accompanied by a relay clicking sound.

Critical safety warning: The high-voltage section (transformer, capacitor, diode, magnetron) can store and generate lethal voltages. Do not attempt high-voltage testing unless you are properly trained and equipped. Always unplug the microwave before any work.

Basic user checks:

• Unplug the unit for 10 minutes, then plug back in and try a short 10–15 second test with a cup of water. If E5 appears again immediately, discontinue use.
• Ensure the outlet is properly grounded and not shared with heavy loads that may cause voltage drops.

Technician-level checks:

• Remove the cabinet and visually inspect the high-voltage capacitor and diode for burn marks, cracks, or melted insulation.
• Check the line fuse and any internal thermal fuses for continuity. Replace only with identical ratings.
• Test the high-voltage capacitor and diode with appropriate procedures and tools; replace any component that tests shorted or open.

Recommendation: Because of the danger involved, most homeowners should not service the high-voltage system. If E5 persists, contact a professional appliance technician or replace the microwave.