A:Answer I have a 50L711U18 and the picture goes dark after a few minutes. Found a “solution” on a forum: unplug all of the inputs and then turn the tv on. You should get the Toshiba symbol showing and then no input. Select an input and then go to picture settings and turn the backlight setting all the way to zero. Do this for all of the inputs you use. Once they are all set to zero, reconnect them to the tv and turn it on. This worked for me, albeit the picture is dark.
Apparently the heat sink needs to be replaced.
Hope this helps!
