Diagnosis
Error code F3 indicates a fault in the door switch circuit. The microwave detects an open circuit when the door is closed.
How to Fix It
Unplug the microwave. Locate the door switches near the door latch. Test each switch for continuity with a multimeter. Replace any switch that does not click or show continuity when pressed.
If That Didn't Work
Check the wiring harness connecting the door switches to the control board for breaks or loose connections.
Heads Up
Use only genuine Hamilton Beach replacement parts. Improper switches can cause safety hazards.