If the display screen doesn't respond at all, it is likely that the display screen cable is loose or there is a poor contact. It is recommended that you go to the after-sales or computer repair site to check.
The video card is loose, which causes poor contact. You can open the chassis and find the connector of the line connected to the monitor. The connector is connected to the video card in the chassis. You can plug it with proper force and it will be OK
