Symptoms
- Interior light doesn't turn on when the door opens or the microwave runs
- Microwave still heats and operates normally otherwise
- Light may have flickered before going out
- Bulb may look visibly blackened if you can see it
Likely causes
- CommonBurned-out light bulbInterior bulbs run in a hot, enclosed space and burn out over time.
- PossibleLoose bulbVibration during use can loosen a bulb enough to break the connection.
- PossibleFaulty light socket or wiringLess common, but possible if a new bulb doesn't fix it.
- Less commonFailed control board relay for the light circuitOn some models, the light is controlled through the main board.
What to do
- Unplug the microwave and let it sit for a minute before opening the case or accessing the bulb.
- Check your manual for the specific bulb access point, which is often behind a small cover on the back or side of the unit, or sometimes just inside the cavity.
- If it's an internally mounted bulb requiring case removal, weigh whether this is within your comfort level, since it involves working near high-voltage components even if unplugged.
- Replace the bulb with the correct type and wattage specified in your manual.
- Restore power and test the light.
- If a new bulb doesn't fix it, or the bulb access requires opening the case, have a technician handle it.
Tools and parts
- Screwdriver
Microwave light bulbSearch: “microwave appliance light bulb replacement”
When to call a pro
If the bulb access requires removing the case, or a new bulb doesn't fix it, call an appliance technician.
Safety
Use caution
If replacing the bulb requires opening the outer case, have a technician do it instead, since internal components can carry a dangerous charge.