Dell Inspiron 15 5000 Setup And Specifications page 22

Function key
The Fn key is also used with selected keys on the keyboard to invoke other
secondary functions.
Function key
22
Re-defined key (for
multi-media control)
Behavior
Turn off/on wireless
Pause/Break
Sleep
Toggle scroll lock
Toggle between power and battery-
status light/hard-drive activity light
System request
Open application menu
Behavior
Play/Pause
Play next track/chapter
Switch to external display
Search
Toggle keyboard backlight
(optional)
Decrease brightness
Increase brightness