How to Troubleshoot an Exhaust Fan on a GE Spacemaker Microwave Model #JVM1660WB003

Verify the microwave is switched on; some models are controlled by a separate switch near the stove below. The fan won't turn on while you are cooking on the stovetop unless the microwave is switched on. Hold the "Clear/Off" button if "L" appears on the display when you switch on the microwave.

Check that the vent fan is turned on; it doesn't activate automatically during cooking like on other models. Tap the "Vent Fan" button on the control panel until you hear the fan working. Each push of the button cycles the fan speed from "High" to "Low" then to "Off."

Slide both of the grease filters beneath the microwave toward the back of the stove and downward to remove. Wash both in hot, soapy water clearing away any blockages. Ideally, the filters should be cleaned every six months. Let both filters dry before returning them to their slot underneath the microwave. Try the vent fan again as in step 1.