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

Hello Paul, You should check the thermostats in the unit including the cavity thermostat 8183999 and the magnetron thermostat 8183994. I'm sorry but these parts have been discontinued by the manufacturer and no satisfactory substitutions have been provided. Thank you for your patience and understanding in this matter.

C Taylor, The magnetron can be tested for less than 1 ohm at the two terminals. Just unplug the connector and be cautious with other high voltage parts in that area. .

Robert, This inverter board should be the only part that would be needed for your issue.

Lonni, In a lot of cases it would be dependent on the supply power. If the 2500 watt inverter is connected to a 12 v battery for instance, the battery would not be large enough to power the Microwave because it will drain the power. It will also depend on the microwave wattage. A 1000 watt microwave for example will consume about 1500 watts while running so depending on the size of the microwave and what type of battery that it is connected to will determine what the inverter can power.

Hello Rob. You will need to replace the fan for the slow start. You most likely have a "high voltage" side malfunction. Transformer, diode, magnetron, Capacitor. You will need to be extremely careful if you decide to test the components with a multi meter, Very high residual voltage is present, so make sure you remove power to the microwave and short across the terminals on the capacitor. The magnetron should have a reading of less than 1 ohm resistance across the two terminals, and an "open" circuit between each terminal and chassis ground. The diode/rectifier should have a resistance reading in one direction only, no resistance, or resistance in both directions indicate a faulty diode. The primary winding on the trans former should read approximately 450 Ohms resistance, the secondary winding should read 80 ohms resistance, and the filament transformer should read 100 ohms resistance. If all the readings are proper and in range, replace the magnetron.

Hello Jim. The inverter 8204961 you need for this issue has been discontinued.

Hello Sam. Yes, based on the error code and the no heat, it does sound like the inverter.

Hello Ray, Because that is the way the manufacturer of the part priced it. This question should be directed toward them. We just sell their parts. We do set the suggested retail price.

Michael, You are on the correct track and the 1100W inverter would be the correct part to replace for a faulty inverter. To check the inverter. Using an ampmeter to measure the input current of the microwave oven when the power level is set to level 10 at the touch panel. If more than .5A then the 1100w Inverter is most likely ok. If less than .5Amps then there is no input to the 1100W inverter. Check the following: No Ac voltage supply. Check control system assembly PCB and wiring. Also check the 4 connectors on the inverter board for loose wires, bad crimping and signs of overheating.

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.