Most ovens have an interior light to make foods more visible as they bake. Heat-resistant windows on oven doors make it possible to see inside while the light is on, without losing heat. Bulbs that burn out are generally located where they can be easily accessed and removed. New oven light bulbs are typically inexpensive and available at most hardware and appliance stores. Monitor the progress of what you bake again with a quick oven light bulb change.
Turn off the oven and oven light. Open the oven door and allow it to cool to room temperature.
Search the upper back corners of the oven interior for a tempered glass dome. Lift off the wire harness on the base of the glass dome, if one is present. Unscrew the tempered glass dome by turning it in a counter-clockwise direction.
Clean the inside and outside of the glass dome with liquid dish soap and a sponge. Rinse off the soap thoroughly. Dry the glass dome completely.
Unscrew the dead oven light bulb. Cover your hands with cotton gloves or clean oven gloves to avoid getting any skin oils on the new bulb. Screw in the replacement light bulb.
Turn on the oven light to test the new bulb. Switch the oven light off. Reinstall the cleaned glass dome and wire clip, if one was present.
Contact the manufacturer or an appliance repair technician if the replacement bulb does not illuminate. There may be a wiring issue or fuse outage.