Why Doesn't My Microwave Turn On Anymore?

Jul 29, 2023, 12:18pm

The microwave has a rotation system consisting of the motor, roller support, tray carrier and glass tray. The role of this system is important, because it allows the waves to be distributed over all the food, for even cooking.

Some parts can be damaged, which is why when it no longer lights up or no longer heats up, it will be necessary to check:

  • food
  • the electrical panel
  • the power cord
  • microwave capacitor
  • microwave fuses
  • the output voltage of the cord
  • the output voltage of the noise filter
  • door security
  • the transformer
  • the magnetron
  • high voltage diode
  • the capacitor

Microwaves are a key component of modern kitchens, offering us the convenience of quickly heating up our meals. But what happens when your microwave suddenly doesn’t turn on anymore? This situation can be perplexing, inconvenient, and frustrating. Understanding the reasons behind this problem can help address the issue effectively. Here are a few possible reasons why your microwave doesn’t turn on anymore.

Why Doesn't My Microwave Turn On Anymore?

Power Issue

One of the most common reasons a microwave won’t turn on is a simple power issue. Ensure that the microwave is firmly plugged into the outlet and the cord is not damaged. Also, verify whether the outlet is functioning by plugging in another appliance.


If the microwave still doesn’t turn on, try resetting it by unplugging it, waiting for a few minutes, and plugging it back in. If the outlet is the problem, you might need to reset your circuit breaker or replace the outlet.

Blown Fuse

Inside your microwave is an internal fuse that can blow if there’s a power surge or if the microwave has a significant electrical fault. If the fuse blows, the microwave won’t turn on.


A blown fuse will need to be replaced. However, because this involves opening up the microwave, it’s recommended that this task is left to a professional to ensure safety and that no additional damage is caused to the microwave.

Faulty Door Switch

Your microwave has safety mechanisms in place that prevent it from operating when the door is open. If one of the door switches is faulty, the microwave might not turn on even when the door is closed.


A faulty door switch should be replaced by a professional appliance repair technician to ensure the microwave operates safely.

Problems with the Control Panel

If the control panel on your microwave is damaged or faulty, it could prevent the microwave from turning on. The control panel sends the signal to the rest of the microwave to start the cooking process.


A faulty control panel can sometimes be fixed by resetting the microwave, but it often needs to be repaired or replaced by a professional.

Age and General Wear and Tear

Like all appliances, microwaves have a lifespan. With regular use over many years, components can wear out and the microwave may stop working altogether.


If your microwave is old and has been having ongoing problems, it may be more economical to replace it with a new one rather than investing in repairs.

Why Doesn't My Microwave Turn On Anymore?


The high voltage diode plays a very important role in your microwave oven: it allows current to flow in only one direction and reduces the risk of damage in the event of a power surge.

  • Perform a continuity test by connecting the test leads of a multimeter set to continuous mode to both ends of the diode.
  • Reverse order of multimeter probes. A diode only needs to be continuous in one direction: a diode blocks the flow of current in one direction and allows it to pass in the other. Therefore, you should only hear a beep or see a value other than 1 for one of your two trials.


The capacitor, located after the transformer, can store about 2500 volts, the output voltage of the transformer. That is why it is very important to unload it before approaching this room.

There are two cases for checking this part:

  • You have a multimeter that has a “capacitance meter” mode: set it to 100mF gauge and place the tips on the capacitor terminals. Compare the value on the display with the value on the capacitor label. If they are very close, it is in good condition.
  • Your multimeter does not have this mode: set it to ohmmeter mode, caliber 200 kΩ and place the multimeter tips on the leads. The displayed value should increase to 200 kΩ and then decrease. If not, then you can replace the capacitor.

It’s crucial to remember that microwaves are complex appliances that use high voltage, and attempting to fix them without the right knowledge and experience can be dangerous. If your microwave doesn’t turn on and the problem isn’t a simple power or outlet issue, it’s best to consult with a professional appliance repair technician.