My laptop goes black?

I'm doing something on my laptop and suddenly everything I have open closes and the screen goes black. I can see that he is still there but nothing works anymore. I have already tried to open the Task Manager, nothing works except pressing the power button.

When I turn it on again everything works as before.

It has happened too often, who can help?

I guess the RAM that it causes some problems. You can try to replace it or to empty it. Otherwise, let's see if you can maybe expand it