Rich C Kinnelon , NJ August 01, 2016 Appliance: General Electric Microwave PEM31SM4SS Would turn on but not heat Replaced high voltage diode and magnetron. GE Profile PEM31SM4SS. First unplug. Need to remove housing first. 2 torque screws and 3 or 4 additional on rear. Two screws (one each side). There are also several black tabs that need to be pulled out from the top. Once all these are removed the outer casing can be removed. Using pliers with rubber handles short the two capacitor prongs to release stored voltage. Then remove diode from capacitor and casing ground screw. To remove magnetron, first remove 2 bottom screws, then 2 top screws, release wire connector, lift casing brace out of the way to access the top 2 screws. unscrew the 2 small screws on top holding the wire connector. Pull out magnetron and install new one. Reconnect everything, plug in and test with cup of water. If work, replace casing. Took about 15 minutes. Read More... 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes Tools: Pliers, Screwdrivers