Laptop screen goes black after a few seconds. Can someone

I have a laptop (acer) and when I start it up I can see something for a few seconds but then the screen turns black, and when I close it up and down I see again what the screen turns black again after a few seconds.

Can someone help me?

Look closely when it turns black. Do you see if necessary. But the picture is very easy? If so, then the Hitner basic lighting of the LCD screen will be defective.

Try connecting an external monitor to see if it holds the picture. If so, the problem is really only in the internal display. Graphics card will be ok then.

Without warranty, the repair or replacement of the internal screen on most laptops amounts to total financial loss. So either a new laptop, or then operate with a cheap external screen.