Have you turned your microwave to warm food just to realize that it doesn’t work despite having power? I understand how frustrating that can be. Fortunately, the microwave not working but has power is a problem you can easily fix without spending a dollar in repair service.
Generally, your microwave is not working but has power because the power diode is dead, there are foreign objects stuck on the door, or the turntable broke. It’s also possible that the thermal fuse blew or the door latch is faulty.
My goal with this guide is simple. I will mention the likely problem causing your microwave not to work despite having power, tell you the possible cause of the problem, and suggest the best possible fix.
Let’s get to it.
5 Reasons Why Your Microwave Is Not Working But Has Power
The table below is a summary of why your microwave is not working but has power. I also suggest the most suitable do-it-yourself solution to each problem.
| Microwave Problem | Possible Cause | Probable Solution | |
| 1. | Power diode not working | The diode is likely broken or has lost its continuity | Test for continuity (the continuity result should be zero). Replace the diode if it doesn’t have continuity. |
| 2. | Foreign objects stuck on the door | Possible human error | Open the microwave door, check for foreign objects and remove |
| 3. | Turntable not turning | A broken couple, guide and carousel out of place, or a faulty tray motor | Replace the brushing coupler if broken, align the turntable guide and carousel cooking if out of place, or replace the carousel tray motor if it doesn’t have continuity. |
| 4. | Blown thermal fuse | The thermal fuse may have blown due to power surge | Remove the thermal fuse and use a multimeter to test for continuity. Replace the fuse if it has no continuity. |
| 5. | Faulty door latch | The door latch may have broken due to forced push or from overuse. | Disassemble the area around the door to access the torsion springs, and latch lever. Check the part for corrosion or damage. Replace the parts in case of any corrosion or damage. |
1. The Power Diode May Be Defective
If your microwave has power but, instead of heating your food, it hums or buzzes, you might be having a power diode issue.
The power diode is primarily responsible for passing high-voltage power to the magnetron. If the part is defective, the microwave will not produce sufficient power to heat food even if the appliance has power.
- Unplug the microwave from power.
- Remove the screws securing the access panel and remove the panel.
- Discharge the capacitor to avoid electrical accidents and take out the power diode
- Set your multimeter to Rx1 and touch the diode terminal with the multimeter probes to test for continuity.
If the diode has continuity, it means the magnetron could be the problem. But if the diode failed the continuity test, get a new one for replacement.
To replace the diode:
- Attach one of the diode’s ends to the capacitor and secure the other end with a screw.
- Reconnect the disconnected wire.
- Reassemble the microwave
- With the repair complete, restore power to the unit and start a cycle to see if the microwave is now heating.
If the unit doesn’t work even after replacing the diode, use a multimeter to test the magnetron for continuity.
Replace the magnetron if it fails the continuity test. To do this:
- Disconnect all the necessary wires and remove the parts that cover your way to the magnetron.
- Unthread the screws securing the magnetron to the microwave and remove it.
- Visibly check the magnetron for any burnout.
If there are burnt out sections, use the multimeter to test its capacitance. The reading should be 2 to 3 ohms. If you don’t get this result, it means the magnetron is defective and therefore requires a replacement.
- Take out the old magnetron.
- Hook in the new magnetron and hold with screws.
- Reconnect all the disconnected wires and fix back all the internal parts.
- Replace the side access panel depending on the side your microwave has its magnetron.
- Plug the system back to power and warm a cup of water to test if the repair took effect.
2. Something Stuck in the Microwave
It is possible that your microwave is not working but has power because a foreign object like a piece of metal found its way into the cooking chamber.
The presence of foreign objects in the heating chamber will result in sparks.
To solve the problem, power off the microwave and open its door to check for any foreign materials preventing the machine from working as it should.
You should also clean the microwaves inside to get rid of oils/grease.
3. The Turntable Isn’t Functioning
Your microwave’s turntable and turntable support may be malfunctioning causing the unit to fail even with power available.
Four parts in your microwave may be causing the turntable to fail. These are the carousel tray motor, carousel cooking tray, brushing coupler, and the turntable guide.
You will find the turntable guide sits below the turntable. Check on it to ensure it is properly aligned, and adjust it if need be.
The brushing coupler on the other hand is where the carousel-cooking tray sits. It is made of plastic and it’s at the base of the microwave. Check if it’s broken and replace it if cracked.
Check if the turntable guide is properly aligned and the carousel-cooking tray sits nicely on the brushing coupler.
If the brushing coupler isn’t broken or cracked, then the carousel tray motor could be the issue. Use a multimeter to test the motor for continuity, and replace the carousel tray monitor if it has no continuity.
4. The Thermal Fuse May Have Blown
Another reason why your microwave isn’t working but has power is that the thermal fuse may have blown.
A microwave thermal fuse is similar to the traditional fuse just that the thermal fuse blows when there is excess heat and the traditional fuse blow when there is excess power.
The thermal fuse will also blow up if you haven’t had the door properly closed to prevent fire accidents.
Use a multimeter to test if the thermal fuse is faulty. If the fuse fails the continuity test, replace with a new one that has the same ampere rating.
- Unplug the microwave from power
- Unthread the screws holding the microwave to the kitchen cabinet and place the unit on a sturdy surface.
- Unthread the screws holding the access panel.
You may need to remove the microwave frame or control panel depending on your microwave’s make and model.
- Remove the faulty thermal fuse and fix the new one. Make sure the thermal fuse installed has specifics that match the one removed otherwise the fix won’t work.
- Reassemble the microwave, and with help, secure it back in the kitchen cabinet and mounting bracket and hold with screws.
- Plug the cord and restore power to the unit.
- Test if the new thermal fuse is working by microwaving a cup of water for 1 minute.
In case the thermal fuse blows up again, the reason could be another part of the microwave is faulty, the fuse was installed incorrectly, or the fuse installed does not match the one replaced.
5. The Door Latch May Have Failed
A microwave can get power but still fail to work because the door latch assembly is damaged or faulty.
Door latches on your microwave will engage when you close the door and disengage when you open the door.
If the torsion springs gets weak or damaged, the microwave door will not hinge and close properly.
- Unplug the microwave’s power cord from the socket to cut off power.
- Open the microwave door and take out the turntable and turntable support.
- Get to the door latch by disassembling the area around the control panel.
- Once you have the damaged lever on sight, remove it.
- Fit in the new door latch.
- Reassemble the control panel and make sure all the wires are connected to the appropriate terminals.
- Lift and fix the microwave back to the kitchen cabinet and mounting bracket – don’t forget to secure it with screws.
- Open the microwave door and fix the turntable and turntable support.
- Restore power to the unit and microwave a cup of water to test if the repair was a successful one.
Frequently Asked Questions
1. What Would Cause a Microwave to Work But Not Heat?
The reason why a microwave is working but not cooking your food is that the magnetron is faulty. You will need to replace the faulty magnetron with a new one to get the microwave to heat food.
2. Will Microwave Work With a Blown Fuse?
No, a microwave cannot work if it has a blown fuse.
You will need to get a new fuse for replacement. In choosing a replacement fuse, you must ensure the new fuse matches the ampere rating of the defective one.
3. Why is My Microwave Not Working All Of a Sudden?
The reason why your microwave has suddenly stopped working is that a fuse has blown due to excessive electric current or heat.
The other common reason why a microwave can suddenly stop working is if the magnetron is faulty.
Final Thoughts
You don’t necessarily have to call a professional if your microwave is not working but has power. You can take advantage of the do-it-yourself troubleshooting and save yourself time and money in repair service.
Simply implement the quick DIY fixes that I’ve shared in this guide and you’ll get the appliance working properly again.
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