Samsung TV flickering and has backlight issues. what could it be?
I got this tv today the image flashes/flickers. it is a un65ks850df. it starts flickering after about 20 minutes or so of use. also it has a second problem that starts right when i turn it on. the backlight goes from high to low ( not gradually) every 30 seconds or so and it wont allow me to change the backlight level in the settings. however i am able to change the brightness and sharpness and contrast, just not the backlight. we sent it to a repair shop and he replaced the main board but it still does the same thing. This is a video of the tv flickering ( the most annoying problem). it goes away sometimes and comes back after a while. Please let me know what it could be. thank you
this is a link of the flickering.