Instructions
Connect the PSP's AC adapter to the PSP itself and to a grounded electrical outlet. Your PSP can achieve the highest brightness levels once connected to this power source.
Turn your PSP on by sliding the power switch up on the right side of the unit.
Press the "Display" button on the PSP. This is the button with a "curved rectangle" located just below the LCD screen. Each time that you press the button, the screen will brighten. There are four levels of brightness on the PSP's screen. Once you press the "Display" button five times, the display will revert back to the lowest brightness setting.