My microwave runs but will not cook.

Hi @peyton1997,

What is the model number of the microwave oven?

Most microwave ovens only have the one fuse so if it runs then it is not the fuse.

It may be that one of the door interlock switches is not operating (or releasing) correctly when the door is closed.

Usually there are 3 door interlock switches in an oven. When the door is closed, 2 operate (close) to complete the circuit for the HV circuit which is used to "cook" the food and 1 releases (opens) so that the HV circuit can function. The HV circuit comprises the HV diode, HV capacitor, HV transformer and the magnetron.

These switches are a safety feature designed to prevent harmful microwave radiation escaping from the oven cavity if the oven is on and the door is opened. They turn both the HV circuit and the start circuit off.

If the switches are all OK you may have to test if the HV circuit components are all OK

Be safety aware when working in microwave ovens. The HV capacitor can store >5000V DC for months even if the power to the microwave has been disconnected for this length of time. This amount of voltage can seriously injure you. The HV capacitor needs to be correctly discharged as soon as it is able to be accessed after removing the cover from the oven and before commencing any further work in the oven.