As for my Galaxy Note 10.1 2014 Edition, I think I've found the culprit. I had the same issue where the screen went black but removing the back reattaching the screen cable fixed it temporarily. What I did to fix was go to "Lock screen" setting and set the "Lock automatically" to "immediately". Ever since I have done it, the issue has gone. It seems there's a software issue but god only knows. I hope this solution works for others too.