Brother MFC-790CW - Manual (Page 47)

General setup
31
3
Setting the Dim Timer for the
backlight
3
You can set how long the LCD backlight stays
on after you go back to the Ready screen.
a
Press MENU.
b
Press a or b to display
General Setup.
c
Press General Setup.
d
Press a or b to display LCD Settings.
e
Press LCD Settings.
f
Press Dim Timer.
g
Press 10 Secs, 20 Secs, 30 Secs or
Off.
h
Press Stop/Exit.