Sony PCG-K27 Manual

Fn+F2 

Toggles the built-in speakers off and on. 

Fn+F3 

Decreases the volume when the Fn key is pressed, and the F3 key is tapped. 

Fn+F4 

Increases the volume when the Fn key is pressed, and the F4 key is tapped. 

Fn+F5 

Decreases the screen brightness when then the Fn key is pressed, and the F5 key is tapped. 

Fn+F6 

Increases the screen brightness when then the Fn key is pressed, and the F6 key is tapped. 

Fn+F7  Toggles the display between the computer screen (LCD), a connected external device, such as a monitor or
projector, and both the LCD and external device. 

Select one display at a time when playing a DVD. Connect the cable before you turn on the computer; otherwise, Fn+F7
may not work. 
Fn+F12 

Puts the system into Hibernate mode, a power management state. To return the system to normal

operating mode, press the power button. Hibernate mode consumes the lowest level of power.