Activation of iMessage/FaceTime failure

It's has appears after a restoration. My iMessage setting stays deactivated. Or when I try to activate it, it fails. No error in particular. Just try again.

It has been more than a month that I try again. Even more.

I don't understand why. For other users, it's working, so, it doesn't seem That the Apple server is down. I am starting to wonder if it is not the hardware that has a problem now. And of course, Facetime doesn't work neither. Same error message. Any help ?