No response when charging gun is plugged in There can be a variety of reasons why the charging gun does not respond when plugged in, some of which are detailed below: 

The charging gun or charging equipment is faulty. It may be that the charging gun line is short-circuited, the charging port is faulty or the charging gun parts are damaged, or the charging equipment is in disrepair, and the internal parts and lines are damaged by aging. 

There is a problem with the vehicle's charging port. It may be that the charging port of the vehicle is faulty, the charging system and battery management system are abnormal.

 Improper operation by the user. For example, charging settings are wrong, charging function is not turned on, etc. The vehicle model is incompatible with the charging equipment. If the charging parameters, charging configuration, etc. are incompatible and unsuitable with the charging device, charging will also not be possible. 

The power switch is not turned on. The switch of the power supply is not turned on, and there is no response when the charger is plugged in. 

Poor wiring contact. If the wiring has poor contact or the plug is loose, it will also cause the charger not to work properly. 

If you encounter this situation, you can check and deal with it accordingly based on the possible causes mentioned above. If you are unable to solve the problem by yourself, it is recommended to leave it to a professional technician to ensure safety and reliability.