Customer Questions and Answers for Inverter (Compressor Drive Board) by Whirlpool

Dave, The F7 Error code indicates that power to the magnetron was interrupted. You will want to make the following checks: 1. Unplug microwave oven or disconnect power. 2. After 40 seconds, check to see whether this solves the problem. 3. Unplug microwave oven or disconnect power. 4. Check resistance of the magnetron thermostat. 5. Check the magnetron. 6. Check wiring to the 1100W inverter and control system. See “Checking Inverters.” 7. Plug in microwave oven or reconnect power. 8. Check operation of all interlock switches. Check door, hinge and cavity front alignment. Adjust as needed. 9. Unplug microwave oven or disconnect power. 10. If switches operate correctly, replace 1100W inverter. 11. If problem persists, replace electronic control. 12. Plug in microwave oven or reconnect power.