1. The high-voltage capacitor of microwave oven is damaged: the high-voltage capacitor is the key component of microwave oven heating. If the capacitor is damaged, the microwave oven cannot be heated. Usually, the damage of high-voltage capacitor will make noise, and it can also be tested by multimeter to confirm whether it is damaged.

2. The microwave oven fuse is blown: The microwave oven fuse is a fuse to prevent overload. If the microwave oven is overloaded or abnormal, the fuse will blow and the microwave oven will stop working.

3. Malfunction of microwave oven magnetron: The high-frequency current output by microwave oven magnetron transfers energy to the inside of microwave oven, thus realizing heating. If the magnetron fails, the microwave oven will lose its heating function. Usually, when the magnetron fails, it will make a sound or smoke.

4. Failure of turntable motor of microwave oven: turntable motor drives turntable to rotate. If this failure occurs, the microwave oven will not work normally. In addition, the turntable motor is also the center of energy transfer inside the microwave oven, and if it fails, it will affect the heating effect of the microwave oven.

5. Microwave oven door switch: The microwave oven door switch is an important sensor inside the microwave oven, which will trigger when the microwave oven door is closed. If the switch is broken or the trigger is not pressed, the microwave oven will not heat up.

If your Samsung microwave oven can't be heated, you can check it by the following steps:

1. Make sure that the socket and power cord are connected properly.

2. Check whether the high voltage capacitor of microwave oven is normal.

3. Check whether the fuse of the microwave oven is blown.

4. Check whether the magnetron of the microwave oven is faulty.

5. Check whether the turntable motor of microwave oven works normally.

6. Check whether the microwave oven door switch works normally.

If the problem cannot be solved, it is recommended to contact Samsung after-sales service center for further inspection and maintenance.