Acer 721TX Service Guide - Page 35

Power Management This computer has a built-in power management unit that monitors system activity. System activity refers to any activity involving one or more of the following devices: keyboard, mouse, drive, hard disk, peripherals connected to the serial and parallel ports, and video memory. If no activity is detected for a period of time (called an inactivity time-out), the computer stops some or all of these devices in order to conserve energy. This computer employs a power management scheme that supports APM (Advanced Power Management) or ACPI (Advanced Configuration and Power Interface) which allows for maximum power conservation and maximum performance at the same time. If your computer is set for APM, you can set time-out values for your computer's devices before power-saving methods are applied to these devices. If your computer is set for ACPI, Windows 98 handles all powersaving chores for your computer. Note: Power management (APM or ACPI) greatly prolongs your battery life. Power Management Modes Display Standby Mode Screen activity is determined by the keyboard, the built-in touchpad, and an external PS/2 pointing device. If these devices are idle for the period specified by the LCD backlight Time-out value, the display shuts off until you press a key or move the touchpad or external mouse. "Automatic Dim" Feature The computer has a unique "automatic dim" power-saving feature. When the computer is using AC power and you disconnect the AC adapter from the computer, it automatically dims the LCD backlight to save power. If you reconnect AC power to the computer, it automatically adjusts the LCD backlight to a brighter level. Hard Disk Standby Mode The hard disk enters Standby mode when there are no disk read/write operations within the period of time specified by the Hard Disk Time-out value. In this state, the power supplied to the hard disk is reduced to a minimum. The hard disk returns to normal once the computer accesses it. Chapter 1 27