Thanks Barb,
It is in my menu. It is named "Centre de commentaires" in french. I have posted a comment with as much details as possible.
I realized that there is another topic about Surface Pro CRAHS" in this community. They say that their Surface craches and that the screen gets black. I am quite sure that it is not a crash, it is only the screen that gets completely black.
The last time that it happened to me I did push the button to put my Surface in sleeping mode and than to wake it back. After 2 or 3 times I got back some luminosity. I could have done also a full restart but didn't have to.