Why is my MacBook Pro internal display not detected?

LeonardoNapolean wrote:

yes it is the internal screen

And the internal screen does work all the time. But when i close the lid and open it again it doesn’t.

but when shut down the mac by pressing shift+control+option+power button. Its starts working again

Try resetting NVRAM/PRAM Reset NVRAM on your Mac - Apple Support

if no resolve try the revive feature—

How to revive or restore Mac firmware - Apple Support

LeonardoNapolean wrote:

Whenever i shut my mac flap down and open it again. My main display doesn’t work but my external display works.

" main display doesn’t work" is this the internal dispaly you are referring to(?)

does your internal display ever work....?