No heating is due to the failure of high-voltage circuit, such as bad high-voltage capacitor, resulting in no high voltage or abnormal high voltage, the magnetron can not work normally and does not produce microwave.

The high voltage diode is damaged, resulting in no heat;

High-voltage fuse 5000KV0.8A is blown, resulting in no heat;

The high-voltage transformer is free from high voltage and heating damage;

The high-voltage transformer has no primary power supply, which leads to the high-voltage circuit not working and not heating the image.

Solutions to the above problems:

Measure the high-voltage capacitor with a capacitance meter, and replace the original high-voltage capacitor if it is damaged;

Replace the high voltage diode;

Replace the high-voltage fuse and press the terminals on both sides;

Replace the high voltage transformer;

Check the primary power supply circuit of transformer and replace the damaged components to ensure the normal primary power supply.