If your microwave is not heating food, but the timer is working, there are a few common issues to consider. First, check the door switch. The door switch signals the microwave to start heating when the door is closed. If the switch is faulty or not engaging properly, the microwave may turn on, but it won’t heat the food. Inspect the switch and replace it if necessary.

Another potential cause is a malfunctioning magnetron. The magnetron is the component that generates the microwave energy to heat the food. If the magnetron is defective, the microwave won’t heat. Testing the magnetron with a multimeter can help determine if it needs to be replaced.

Additionally, check the high-voltage diode. The diode works with the magnetron to produce heat, and if it’s damaged or faulty, the microwave may not heat food. Replacing the diode may resolve the issue.

Lastly, ensure that the microwave is receiving proper voltage. Microwaves require a sufficient power supply to operate correctly. If the outlet or power supply is faulty, the microwave may not heat even if it appears to be functioning normally.