How to Fix Samsung Microwave not Heating?

Microwaves are essential appliances in most kitchens for quickly heating up or defrosting foods. However, it can be incredibly frustrating when your microwave stops heating properly.

If you have a Samsung microwave that is running but not heating food, there are a few things you can try yourself to fix the issue before calling for service.

Troubleshoot the Basics First

Before diving into repairs, first run through some basic troubleshooting steps:

Check that the microwave is plugged in and the outlet is working. Make sure the microwave is fully plugged into a working outlet. Unplug it and plug it back in to reset the connection. Try plugging something else into the outlet to confirm power is flowing properly.
Inspect the door and make sure it is properly closed. Microwaves have safety sensors that prevent them from running if the door isn’t completely closed. Open and firmly shut the door, making sure it latches properly.
Check the turntable. Ensure it is rotating freely when the microwave runs. If not, try cleaning it and making sure nothing is obstructing it.
Test different power levels and cook times. Try cooking something on high power for 30 seconds to 1 minute. Attempt medium and low power as well. This helps determine if only certain power levels aren’t working.
Remove obstructions. Look inside the microwave and ensure no food, utensils, or other items are blocking the path from the door to the back wall. Anything that obstructs this path can impact heating.
Allow the microwave to cool fully after use before troubleshooting. Running through diagnostic tests on a hot microwave can lead to inaccurate results. Let it cool down completely before testing settings.

Inspect the Magnetron

If the basics check out but food still isn’t heating, the issue likely lies with a faulty magnetron. This is the part responsible for creating the microwaves that cook food. With the microwave unplugged, follow these steps:

Remove the outer cabinet. This usually just requires unscrewing a few screws on the chassis. Consult your owner’s manual for exact locations.
Once the cabinet is off, locate the magnetron, which is a tube-shaped component. Examine it for any visible damage like cracks or loose wiring.
If you have a multimeter handy, test the magnetron’s continuity by touching the multimeter leads to the magnetron’s two terminals. If the magnetron is fine, you should get a very low resistance reading. An overload or short reading indicates it needs replacement.
Inspect where the magnetron plugs into the power supply for any damaged wiring. Make sure the connection is secure.
If the magnetron is cracked, the wiring is compromised, or testing reveals issues, the magnetron will need to be replaced. Consult a service manual and only attempt this if you are highly experienced with electronics repair.

Check the High Voltage Diode

The high voltage diode works in conjunction with the magnetron to transform low voltage electricity into high voltage energy that powers the microwave generation. To test:

Again with the microwave unplugged, remove the outer cabinet to access internal components.
Find the high voltage diode, which is usually located near the magnetron. It may be cylindrical or rectangular shaped.
Use a multimeter to test its continuity. Little to no resistance means it is likely functioning. Infinite resistance means it is likely bad and needs to be replaced.
A faulty high voltage diode is not user serviceable and requires professional installation of a new diode. Do not attempt replacement on your own due to high voltage risks.

Examine the High Voltage Capacitor

The high voltage capacitor stores the electricity that powers the magnetron. When it fails, it can prevent the magnetron from properly receiving power.

The capacitor may be a small black cylinder with two terminals, located near or attached to the magnetron.
Before testing, discharge the capacitor. With the microwave unplugged, use an insulated screwdriver to touch both terminals and release any stored electricity, completing the circuit.
Use a multimeter to test the capacitance between the capacitor’s terminals. Consult your microwave’s service manual for the proper capacitance reading (usually above 2000pF). A low reading indicates it should be replaced.
Again, because this component operates at high voltage, it is recommended to hire a professional for the actual replacement.

Inspect the Thermal Fuse

Microwaves contain a thermal fuse that blows when the appliance overheats, cutting power to prevent a fire hazard. If the fuse blew, the microwave will run but not heat.

Find the thermal fuse which looks like a thin white plastic strip with a wire coming out each end. It is typically located on or near the magnetron.
Use a multimeter to test continuity across the wires. No continuity means the fuse is blown and must be replaced.
Replacement fuses are inexpensive and available online or at appliance parts stores. However, frequent fuse blowing usually indicates an underlying issue needing repair, like a problem with the door, magnetron or other component.

Check the Door Sensors

Microwaves have multiple safety door sensors that prevent the appliance from running when the door is open. Faulty sensors can also lead to lack of heating.

Open the door and locate the door sensor switches, usually small plastic arms or levers along the door’s sides.
Try pressing them in manually one at a time and listen or watch for the turntable and interior light to shut off. Do this also with the door closed.
If the sensors are stuck and don’t react properly, they will need to be adjusted or replaced to restore normal function.

Replacing door sensors may require soldering and electronics expertise. Having an authorized Samsung service center handle any sensor replacements is recommended.

You’re right, my original article focused more on troubleshooting the issue rather than providing solutions. Here is an updated version with more details on how to actually fix the common issues that cause a Samsung microwave to run but not heat:

How To Fix A Samsung Microwave That Doesn’t Heating

When your Samsung microwave runs but fails to heat food, it’s likely due to an issue with one of several internal components. Here are some steps to help diagnose the problem and get your microwave heating properly again.

Test the Magnetron

The magnetron converts electricity into microwave energy to cook food. To test:

Unplug the microwave and remove the outer case.
Inspect the magnetron for any cracks or damage.
Use a multimeter to check continuity between the two magnetron terminals.
If there is no continuity, or the reading is overload/short, the magnetron needs to be replaced. Replacement parts can be found online or at appliance parts stores.
Carefully disconnect old magnetron and install the new part. Reassemble the microwave. Test to see if heating is restored.

Replace the High Voltage Diode

The diode directs electricity from the transformer to the magnetron. To test:

With microwave unplugged and outer case removed, locate diode near the magnetron.
Check diode continuity with a multimeter. Any indication of an open circuit means it needs replacement.
Order a replacement high voltage microwave diode online or from an parts supplier.
Carefully remove old diode and install new one in same position. Reassemble and test microwave.

Swap Out the High Voltage Capacitor

The capacitor stores energy for converting into microwave power. To test:

Discharge the capacitor by shorting terminals with insulated screwdriver.
Check capacitance with multimeter. Capacitance should match service manual specs (usually over 2000pF).
If capacitance is low, order proper replacement capacitor online or from appliance parts store.
Disconnect old capacitor, install new one, reassemble microwave, and test for proper heating.

Replace Blown Thermal Fuse

If the thermal fuse has blown, the microwave won’t heat. To replace:

Remove outer case and locate thermal fuse near the magnetron.
Check fuse continuity with multimeter. No continuity means it’s blown.
Order replacement thermal fuse designed for Samsung microwave.
Swap out old fuse with new one, reassemble unit, and confirm heating works.

Adjust or Replace Faulty Door Sensors

Open microwave door and inspect plastic lever sensors along edges.
Manually press them while unit is open and closed to check operation.
If levers are stuck, try cleaning and straightening to restore function.
If sensors are defective, order replacements designed for your Samsung model.
Swap in new door sensors and test if microwave now heats properly.

With the proper diagnosis and replacement of any faulty parts, you can get your Samsung microwave heating foods again. Always exercise caution when working with microwave high voltage components. Call a technician for any repairs you are uncomfortable handling.

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How to Fix Samsung Microwave not Heating?