Why do black squares appear on the screen from time to time?

Question

laptops

They took a new laptop, from time to time, from one to three black squares appear on the screen not very often, like when you point to some programs. They can appear in different places, and immediately disappear. Help, I don't know what to do.

Answer 1

The matrix may be damaged.

Answer 2

Try to check if the artifacts are related to the matrix or to the video adapter. To do this, take an external monitor (if not, then borrow it from someone), connect it to a laptop, work in two modes:
1) the picture is only on the external monitor, the laptop screen is off; will there be artifacts?
2) duplication of a picture from the laptop screen to an external monitor; try to notice if the artifacts are duplicated or are they only on the laptop screen?