Answer to "TCL TV keeps flashing black on and off"Mine has been doing the same thing. Sometimes on the left, sometimes on the right. It works in conjunction to the screen TVbrightness/PictureMode. If I set to Normal/Normal, all is ok. If I raise either 1 of the 2 settings to a brighter screen, such as bright or vivid or enhanced, I get the flicker. Also, changing the backlight level higher will cause it as well. Annoying, but will put up with if for a while, until it gets worse or goes out. If I have to replace it, will go back with the same TV I guess. TCL Roku 55” 4K.