MacBook Pro no backlight after PRAM reset

The MacBook was displaying vertical lines like these:

https://encrypted-tbn0.gstatic.com/image...

The sounds and system were responding normally, even cursor movement caused changes in the vertical lines.

A PRAM reset was performed, after which the display simply stopped working, no backlight. The system can still be accessed through an external monitor.

In the system information, the internal display seems to not be recognized. I tried removing and reinserting the display into the logic board, but it didn't work.

I need to know if the problem is with the display or with the MacBook. If it's with the display, I'll look into whether I can replace it."