Samsung Galaxy Tab A
Set display brightness
Slide your finger down the display starting from the top edge of your tablet.
Press Auto to turn automatic brightness on or off.
Press Auto to turn automatic brightness on or off.
If you turn off the function:
Press and drag the indicator next to the brightness icon right or left to set the display brightness.
Press and drag the indicator next to the brightness icon right or left to set the display brightness.
Return to the home screen
Press the Home key to return to the home screen.