Symptoms
• Microwave will not start or begin cooking cycle
• Error code E3 displays on the control panel
• Door appears to close normally but microwave does not recognize it as secure
• Unit beeps and displays error when attempting to start
• Door may feel loose or not latch firmly into place
• Microwave stops mid-cycle and displays E3
• Control panel lights remain on but heating does not occur
Possible Causes
• Door latch mechanism is worn, bent, or damaged
• Door interlock switch has failed or lost electrical continuity
• Door strike plate is misaligned or obstructed
• Foreign debris or food particles lodged in the door latch assembly
• Loose or corroded electrical connections on the interlock switch
• Door gasket seal is deteriorated causing improper door closure
• Control board failure preventing proper signal recognition from door switch
• Microwave not receiving proper 120V power supply to door switch circuit
Safety Checks You Can Do
• Unplug the microwave from the 120V outlet and wait 60 seconds, then plug it back in to perform a hard reset
• Visually inspect the door latch and strike plate for any visible damage, cracks, or debris
• Carefully clean around the door latch assembly and strike plate area with a dry cloth to remove dust, grease, or food particles
• Close the door firmly and listen for a definitive clicking sound indicating proper latch engagement
• Check that the door gasket (rubber seal) is not cracked, flattened, or deteriorated
• Verify the microwave is plugged into a dedicated 120V outlet as recommended by USA electrical codes, not a shared circuit
• Check your home's circuit breaker to ensure the microwave circuit breaker is in the ON position
• Open and close the door 5-10 times slowly and deliberately to see if the error clears
• Inspect the interior edge of the door frame for any obstructions preventing full closure
• If the unit is an over-the-range model, check that cabinet or ductwork above is not pushing down on the unit
Safety First
Always disconnect the appliance from power before performing any checks. If you are unsure about any step, please contact a qualified technician.