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How to Change the Magnetron in a Whirlpool Microwave Oven

The magnetron in a Whirlpool microwave oven transforms high-voltage electricity into the microwave energy that heats the food in the microwave. A magnetron contains an anode that surrounds a heated cathode. As the microwave's high-voltage electric circuit applies power to the magnetron's input terminals, the cathode's heating element energizes. The magnetic chambers in the anode cause electrons in the cathode's heating element to spiral outward in an oscillating pattern, forming the microwave energy. Always change a faulty Whirlpool microwave's magnetron with a direct replacement part designed for the particular Whirlpool model.

Things You'll Need

  • Screwdriver set
  • 20,000-ohm resistor
  • Needle-nose pliers
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Instructions

    • 1

      Disconnect the Whirlpool microwave's electric source. If the microwave uses a power cord with a wall plug, pull the wall plug from its receptacle. If the microwave hard-wires into the kitchen's electrical circuit, turn off the circuit breaker controlling the kitchen's electrical appliances.

    • 2

      Remove the two screws holding the microwave's exhaust grill against the top of the microwave, using a Phillips screwdriver. Slide the top of the exhaust grill toward the microwave's door and lift the grill off the microwave.

    • 3

      Open the Whirlpool microwave's door. Remove the control panel's mounting screws, located on top of the control panel, with a Phillips screwdriver. Move the top of the control panel forward with one hand. Reach behind the control panel and pull the two electrical connectors from the back of the control panel with the other hand. Remove the control panel from the microwave.

    • 4

      Slide the Whirlpool microwave's high-voltage access panel's mounting tab out of the cover's slot and remove the cover. The cover mounts behind the control panel's opening near the top of the microwave and protects the high-voltage electrical compartment.

    • 5

      Discharge the Whirlpool microwave's capacitor, located at the front of the high-voltage electrical compartment, with either a 20,000-ohm resistor or a screwdriver with an insulated handle. If using a 20,000-ohm resistor, touch one resistor lead to the capacitor housing and the other resistor lead to each capacitor wire terminal. If using a screwdriver with an insulated handle, grip the insulated handle and arc the screwdriver blade across both capacitor terminals.

    • 6

      Pull the wire connectors and rectifier from the microwave's high-voltage capacitor, using needle-nose pliers for leverage. The rectifier's lead connects to the capacitor's bottom wire terminal.

    • 7

      Loosen the screw holding the capacitor's mounting bracket, using the Phillips screwdriver. Pull the bracket, rectifier and capacitor from the Whirlpool microwave. The rectifier's common lead wraps around the bracket's screw.

    • 8

      Loosen the four screws holding the microwave's high-voltage transformer in place. Slide the transformer out of the way, exposing the magnetron's mounting screws.

    • 9

      Pull the wire connector off the Whirlpool microwave's magnetron wire terminal. Loosen the magnetron's mounting screw, located on the side of the magnetron's mounting bracket. Pull the magnetron from the Whirlpool microwave.

    • 10

      Set the new magnetron in the Whirlpool microwave, keeping its wire terminal facing the front of the microwave. Tighten the magnetron's mounting screw with the Phillips screwdriver.

    • 11

      Snap the magnetron's wire connector into its wire terminal.

    • 12

      Position the high-voltage transformer in its slot in the Whirlpool microwave. Tighten its mounting screws with the Phillips screwdriver.

    • 13

      Set the high-voltage capacitor in its slot, keeping the capacitor's wire terminals facing left and the capacitor's identification label facing toward the front of the microwave.

    • 14

      Position the capacitor's mounting bracket and rectifier in the Whirlpool microwave. Insert the mounting bracket's screw through the rectifier's common lead and the mounting bracket's screw hole. Tighten the screw with the Phillips screwdriver.

    • 15

      Push the capacitor's wire connectors onto the capacitor's wire terminals. The connector with the rectifier snaps onto the bottom capacitor terminal, and the connector with the single wire attaches to the top wire terminal.

    • 16

      Hold the Whirlpool microwave's high-voltage access panel in place. Push the mounting tab into the panel's slot.

    • 17

      Slip the control panel's two wire connectors onto the panel's two wire terminals. The 11-pin connector attaches to the 11-pin terminal, and the two-pin connector attaches to the two-pin connector.

    • 18

      Slip the control panel into its slot on the face of the Whirlpool microwave. Reinsert its mounting screw and tighten with a Phillips screwdriver.

    • 19

      Press the Whirlpool microwave's exhaust grill against the top of the microwave. Secure the grill to the microwave with the grill's mounting screws.