A:Answer I just purchased this model a few days ago and had the same issue. To further add to above answers, 2 things I discovered:
1) It seems that if the light sensor senses that there is enough light to see the keyboard, it turns off the keyboard backlight, regardless of any settings you have chosen. The light sensor is a tiny pinhole at the top left above the keyboard, to the right of the tiny blue power light that you see when the computer is turned on. When I cover that hole, the backlight obeys my backlight settings, even when I am in a brightly lit area.
2) The Samsung Settings, which control the keyboard backlight settings, are NOT the same as the settings in the computer’s Control Panel. To find Samsung Settings, in the white search box at the bottom left of you computer screen, click in the white box and type Samsung Settings. Click on Samsung Settings at the top of the list that appears. In the window that opens, click on Input. There are your keyboard settings. Choose your options and close the window.
In my experience, the computer will obey the options I selected for my keyboard backlight settings as long as I am a) in a dark area OR b) I cover my light sensor.