James for Model Number LVM1750SM1SS Microwave is not heating. I replaced one of the thermal switches because it showed bad. But now when I plug it in the fan runs and will not shut off. I let the fan run for over 30 minuets to see if it would reset itself but it didn't shut off. The replacement switch I used is (22-WB27X1127). The other thermal switch showed good as well as all door switches, fuse, capacitor and diode. There is no heat around the oven because the stove has not been on. I don't know if the microwave heat is working yet because I haven't tried heating anything yet. ?????
Answer James, It sounds like you replaced the fan thermostat. That is supposed to be open until it reaches a certain temperature then it will close and the fan comes on. Check the terminals on the magnetron for less than 1 ohm of resistance. If it fails then replace the magnetron. Read More... Answered by AppliancePartsPros.com | Tuesday, December 17, 2019