Microwave stops during cooking and displays E3; may occur a few seconds after pressing START.

Critical safety warning: Microwaves contain a high-voltage capacitor that can retain a lethal charge even when unplugged. Do not touch or service the high-voltage section (magnetron, transformer, capacitor, diode) unless you are properly trained and equipped.

• Ventilation check: Ensure the microwave has proper clearance per the Danby manual (usually several inches on sides, top, and rear). Remove any items blocking vents.
• Clean vents and filters: For over-the-range models, remove and clean the grease filters with warm soapy water, dry completely, and reinstall. Vacuum dust from intake and exhaust vents.
• Cooling fan operation: Run the microwave with a cup of water for 1–2 minutes and listen for the internal cooling fan. If the fan is not running or is very noisy, the fan motor may be failing.
• Thermal reset: Unplug the unit for 30 minutes to allow internal thermostats to reset. Try again with a small load of food and short cook time.
• Next step: If E3 returns quickly, the magnetron, thermostat, or high-voltage components may be defective. Due to shock risk and radiation shielding requirements, contact a qualified microwave technician for diagnosis and part replacement.