v The ring indicator (RI) is signaled by a serial device or a PC Card device.

v The time set on the resume timer elapses.

Note: The computer does not accept any input immediately after it enters

standby mode. Wait a few seconds before taking any action to reenter operation

mode.

Hibernation mode
In hibernation mode, the following occurs:

v The system status, RAM, VRAM, and setup data are stored on the hard disk.

v The system is powered off.

Note: If the computer enters the hibernation mode while it is docked to the

ThinkPad Advanced Dock or ThinkPad Advanced Mini Dock, do not undock it
before resuming normal operation. If you do undock it and then try to resume
normal operation, you will get an error message, and you will have to restart the
system.

To cause the computer to enter hibernation mode, do any of the following:

v Press the Fn+F12 keys.

v If you are using the APM operating system and have set the mode to Power

switch mode [Hibernation], turn off the power switch.

v If you are using the ACPI operating system and have defined one of the

following actions as the event that causes the system to go into hibernation
mode, perform that action.

– Closing the lid.

– Pressing the power button.

– Pressing Fn+F4 keys.

Also, the computer goes into hibernation mode automatically in either of the

following conditions:

v If a “hibernation time” has been set on the timer, and if the user does not do

any operation with the keyboard, the TrackPoint, the hard disk drive, the
parallel connector, or the diskette drive within that time.

v If the timer conditions are satisfied in suspend mode.

v If you are using the APM operating system and have set the mode to Hibernate

when battery becomes low, and the battery charge becomes critically low.

When the power is turned on, the computer returns from hibernation mode and

resumes operation. The hibernation file in the boot record on the hard disk drive is
read, and system status is restored from the hard disk drive.
38 ThinkPad T500 and W500 Hardware Maintenance Manual