Microwave interior light does not come on when cooking or when the door is opened, but the unit heats normally.

Safety Warning: Unplug the microwave before attempting to replace the bulb. Some models require cabinet removal, exposing high-voltage components.

Steps:

• Consult your Insignia manual to locate the lamp access panel. Some models have an external access cover; others require removing the outer cabinet.
• Unplug the unit and remove the access cover.
• Carefully remove the old cavity bulb (note type and wattage) and install an identical replacement rated for microwave use.
• Check that the bulb is seated firmly in the socket.

If a new bulb does not light, the issue may be with the lamp relay or wiring, which requires a technician to diagnose.