First i was watching youtube on it then i closed it and went. When i came back and open it it blinks a high brightness and the light went off anf it never works again
Can you see video if you shine a flashlight on the screen? If so, your backlight died. Usually that is a part of the screen and can't be replaced seperatly.
If not, it could be the video driver, sometimes replaceable, sometimes on the MB. Or it could be the screen.