What is the reason of my laptop's display doesn't work properly?

@jayeff, thank you for your reply. I connected an external monitor to the laptop ant it works well. When this problem just appeared, I tilted the monitor and the problem disappeared. Now tilting doesn’t affect anyhow. Perhaps I can clarify somehow wheather it is cable connections problem or display panel problem?

Hi @oscar_isaac ,

You could try pressing very gently with a finger, around the hinge area (don't know which one left or right) to see whether it has any affect on the problem.

This is where the video cable passes through from the case to the lid. It may be that the cable is damaged in this area.

Other than that you'll have to dis-assemble it (use the video) to check that the video cable connection to the display panel is OK. (As the lid moves more than the case I suspect this connection more than the motherboard video cable connection but I've been wrong before;-)

After that unfortunately the only way to tell is to try a new cable or a new panel.

You may be lucky and find a supplier that may accept return of parts and give a refund, for only a small restocking fee cost, to minimize the cost to you.

Sorry that I can't be of more help.

I got it, @jayeff, thank you for your help, I will try to disassemble the laptop.