DifficultyEasy

Time10–25 minutes

What you saveBulb $5–$30 DIY vs $70–$180 professionally

⚠️ BEFORE YOU START

Unplug the microwave first — the bulb circuit is live even when the microwave is idle. Never remove the outer metal cabinet of a microwave. The high-voltage capacitor inside stores a charge that can kill you, and it holds that charge after the unit is unplugged. Every step in this guide stays outside the cabinet or inside the cooking cavity — if a repair needs the case off, it is a job for a technician. Only attempt the bulb if it is reachable from outside the cabinet; on many models the cooktop light is, and the cavity light is not.

Tools

Screwdriver
Step stool
Gloves or a cloth

Parts

Appliance-rated bulb matching the manual’s type and wattage $5–$30

Step by step

1 Buy the right bulb before you start

Check the manual or the label for the type and wattage. Appliance bulbs are built for heat and vibration; a standard household bulb in a microwave fails within weeks, and an over-wattage bulb can damage the housing.
2 Unplug the microwave

Never change a bulb on a live appliance. On an over-the-range unit the outlet is in the cabinet above.
3 Find the access cover

On most over-the-range microwaves the cooktop light sits behind a small lens or plate on the underside, held by one or two screws. If your model’s bulb is only reachable by removing the outer cabinet, stop here and book a technician instead.
4 Remove the cover and the old bulb

Undo the screws and lower the lens. Use a cloth or gloves — bulb glass is fragile and there may be sharp edges if it has shattered.
5 Fit the new bulb

Handle it with a cloth rather than bare fingers, particularly on halogen types where skin oils shorten bulb life. Screw or push it in until it seats, without forcing.
6 Refit the cover and test

Replace the lens and screws, plug the unit back in, and switch the light on. If it does not light with a known-good bulb, the socket or the control is at fault.

🔧 WHEN TO CALL A PRO

If a new, correct bulb does not light, the socket has probably corroded or the light circuit through the control board has failed. On over-the-range units the cooktop socket lives in steam and grease for years, and replacing it is inside-the-cabinet work. If you'd rather skip it entirely, find a microwave repair pro near you →

Sources

Where the safety, regulatory and warranty claims on this page come from. Repair costs are our own figures based on Arizona market rates and OEM parts pricing.

Microwave Ovens — Radiation-Emitting Products U.S. Food & Drug Administration The federal requirement for two independent door interlocks plus a monitoring system, and the 21 CFR 1030.10 leakage limit — why an interlock must never be bypassed.