How to Fix LG Microwave Error F9

Error Code: F9 Difficulty: Hard

Problem: This indicates a magnetron or inverter error.

How to Fix F9 Error (Step-by-Step)

1. Unplug the microwave from the wall outlet immediately. This repair involves exposure to extremely high and potentially lethal voltage.
2. CRITICAL SAFETY STEP: You must discharge the high-voltage capacitor before proceeding. Carefully use a screwdriver with a well-insulated handle to touch one metal terminal of the capacitor to the other metal terminal simultaneously. You may see a spark and hear a pop, which indicates the capacitor is discharged.
3. Remove the outer casing of the microwave by unscrewing the panels on the back and sides.
4. Locate the magnetron and the inverter board. The magnetron is a box-shaped metal component, and the inverter is a circuit board that powers it.
5. Carefully disconnect the electrical connectors from the magnetron and remove the screws or nuts holding it in place. Note the orientation of the old part before removing it.
6. Install the new magnetron and/or inverter assembly, ensuring all screws and electrical connections are secure.
7. Reassemble the microwave’s outer cabinet, plug the unit in, and test by heating a cup of water for one minute.
8. Turn the appliance off, wait about 2 minutes, then turn it back on.

Next Steps and Parts

Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.