Toshiba Satellite A200 User Manual page 128

The Keyboard
Instant security: Press Fn + F1 to enter "Lock computer" mode. To restore
your desktop, you need to log on again.
Power Plan: Pressing Fn + F2 changes the power settings.
Sleep: Pressing Fn + F3 switches the system to Sleep mode.
Hibernation: Pressing Fn + F4 switches the system to Hibernate mode.
Output: Pressing Fn + F5 changes the active display device.
Brightness Down: Pressing Fn + F6 decreases the computer's display panel
brightness in individual steps
5-4 User's Manual