Antwoord op "43 inch 4K smart samsung TV with Back light flashing"I had the same model of TV and the same thing happened to me. This solution was is that moisture builds up and causes the motherboard to go off on safety. The first thing to do to get your TV working properly is to get a small hair dryer or heater and point it behind the ventilator slots in the back of your TV make sure it is not too close or gets too hot behind your TV, make sure it sits for about 2 to 3 hours leave the TV unplugged while you're doing this. Keep trying to TV after two or three hours until it comes on. Now what's your TV is on you need to go to settings and under settings you go to Power settings ... Under power you'll find a category that say instant-on you want to keep that on all the time so that motherboard stays warm that doesn't collect moisture. It will say "may use a little bit of more electricity" ... but it's well worth the trouble of getting heaters out and going through the process I just explained.