MacBook Pro screen turns black

It sounds like there is a loose cable somewhere.

The hinge has cables that help the display work.

When someone presses back the monitor to overstretch the hinge, the cables can fray and cause display issues.

If you suspect the computer has been bumped into or has been hit by sudden motion, bring it in to service to have it looked at.

Energy Saver/Power settings on Apple menu -> System Settings as well as Screen Saver on Desktop/Screen Saver have "hot corners" which if activated by the cursor being near one corner of the screen will blank out the screen.

If the security settings are set to put the computer to sleep after a period of inactivity that could be a problem too, and cause coincidental power shut off.

The guys at the Genius bas at an Apple-owned store put their hands on these computer, all day every day.

Chances are they have already seen and fixed this problem many times over. Your appointment for an evaluation is free, in warranty or out.