Microwave Not Heating Food but Still Runs? How to Fix It

Fixing your microwave yourself can save a significant amount of money and is often doable with common tools found in your garage. However, caution is essential, as microwaves are powerful appliances that can pose a shock risk. To minimize the chance of injury, make sure to unplug the microwave and discharge the capacitor before starting any repairs.

COMMON PROBLEMS AND HOW TO FIX THEM 

1. Magnetron

A broken magnetron is the most common reason why a microwave runs but doesn’t heat food. The magnetron is essential for creating the microwaves that heat food. It can become damaged if the appliance is run without food inside, or due to broken magnets and loose connections.

If the magnetron is broken, it can’t be fixed and will need replacement. This can be an expensive repair, so it’s often more cost-effective to buy a new microwave. However, if you have spare parts on hand, replacing the magnetron is worth considering before replacing your microwave.

Signs of a Broken Magnetron

• The microwave runs but doesn’t heat food.
• The microwave makes unusual noises, such as a loud humming, vibrating, or clicking sound.
• On inspection, one of the two magnets appears broken, or the metal cylinder inserted into the microwave shows discoloration (it’s no longer silver).

How to Replace a Broken Magnetron

1) Unplug the microwave and unscrew the side panel to access the components, including the magnetron. The magnetron is a small, metallic, box-shaped component screwed into the microwave.

2) Discharge the capacitor by using a large screwdriver or pliers with an insulated handle to touch the metal.

3) Disconnect the wires attached to the magnetron and keep the screws safe.

4) Install the new magnetron by fitting it into place and securing it with the original screws. Ensure the replacement magnetron is the same model.

5) Reconnect the wires to the new magnetron and reattach the microwave’s side panel.

Finding a Replacement Magnetron

Magnetrons vary in shape, size, and configuration, depending on the microwave model. Brands like LG, Panasonic, and Samsung each have specific designs. Each magnetron has a sticker with the brand name and model number. To ensure compatibility, the replacement magnetron should have the same model number as the original.

2. Broken Door Switch 

The microwave door switch usually stops microwaves from being generated when the microwave door is open. The door switch is located inside the door of the microwave and is normally about an inch long with metal prongs attached. If the switch is broken, the microwave may appear to be working but will not be generating any microwaves and will not heat the food. Replacing a door switch is usually quite inexpensive as they are commonly used in other appliances. Some microwaves though will not run at all if the door switch is broken.

Signs your door switch is faulty

1) When using your microwave, the turntable does not turn and the microwave does not heat up 

2) The microwave light does not come on when the door is opened

How to replace a broken door switch 

1) Unplug the microwave

2) Remove the control panel by unscrewing the face or rims of the microwave

3) Remove the wiring attached to the control panel, taking a reference photo to use when reconnecting the board 

4) Unscrew the switch assembly located on the side, sliding it out of place as necessary  

5) Remove the connectors attached to the switch assembly, again taking reference photos to use later 

6) Test for the defective switch using an odometer, or isolate the broken switch by looking for any signs of erosion

7) Remove the faulty switch, either by unscrewing or unclipping the switch 

8) Screw, or clip in a replacement switch 

9) Reassemble the microwave, plugging in all the necessary wiring and screwing in the brackets and face that was removed   

Finding a replacement door switch

It is important that the right door switch is used so that your microwave is able to operate. Parts will usually need to be bought from the same brand and have the right number of terminals – usually 2 or 3. The switches will also be ‘usually open’ or ‘usually closed,’ it is important to choose the right one. 

4. Contact Support

If the issue persists after following the steps above, please visit Samsung Repair or contact Appliance Repairs Guru for further assistance. They can provide more specific guidance or schedule a service visit if necessary.

Always refer to your microwave’s user manual for specific instructions and safety precautions related to troubleshooting and repairs.