screen backlight won't turn on after locking or turning it off

I have this problem also. Would love a fix...

I had the same problem... just appeared today. I was able to solve it by changing my screen lock from Pattern to Swipe. I let the screen turn off and then was able to push the center button and it lit back up. Following this I was able to move my screen lock back to Pattern.

Almost seems like something was corrupt with the lock screen... odd that it only did it after locking.

Hope this helps