Lenovo Y40-70 - Manual (Page 13)

Chapter 1. Getting to know your computer
7
The following describes the features of each function key.
Fn + F1:
Enters sleep mode.
Fn + F2:
Turns on/off the backlight of the LCD screen.
Fn + F3:
Opens the interface for selecting display options.
Fn + F5:
Enables/disables Airplane mode.
Fn + F6:
Enables/disables the touchpad.
Fn + F9:
Opens the Settings charm.
Fn + F10:
Opens the Search charm.
Fn + F11:
Displays current apps.
Fn + PrtSc:
Activates the system request.
Fn + Insert (Lenovo
Y50-70/Y50-80/Y50-70
Touch/Y50-80 Touch):
Fn + PgUp (Lenovo
Y40-70/Y40-80):
Enables/disables the scroll lock.
Fn + Home:
Activates the pause function.
Fn + End:
Activates the break function.
Fn + PgDn (Lenovo
Y40-70/Y40-80):
Activates the insert function.
Fn + / :
Increases/decreases the display brightness.
Fn + / :
Increases/decreases the volume.
Fn + Space 
(on select models):
Adjusts the keyboard backlight 
(off  dim  bright  off).