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Document ID: GSMH-3B4L8C

TP 355,360,370,750,755C/CS - Power Management Features

Applicable to: World-Wide

Power Management Features:
Three power management modes are provided by the computer to save power consumption and prolong battery power.

Standby Mode:
When in standby mode the following occurs:
- The LCD backlight turns off.
- The hard disk motor stops.
- The CPU clock is set to the lowest speed.

Events that cause entering of standby mode:
- Standby requested by the Fn key. (Fn+ F3)
- No activity under auto-standby enabled by the feature utility.

Events that cause exiting or resuming of standby mode:
- (Resume) Any key operation.

Suspend Mode:
When in suspend mode, the following, in addition to the four actions of standby mode, occur:
- The LCD power is powered-off.
- The hard disk is powered-off.
- The CPU is stopped.

In the ThinkPad Features Program, the computer can be set to 'Will not suspend even if LCD is closed.—.

When the computer is powered with ac power and is used with one of the following IBM PC cards, the computer enters standby mode ; the PC card and application program remain active.
- 3270 Emulation Credit Card Adapter
- 5250 Emulation Credit Card Adapter
- Token-Ring 16/4 Credit Card Adapter
- Credit Card Adapter for Ethernet

In the following condition, the computer cannot enter the suspend mode.
- While the communication link is running.
- When a serial mouse or other pointing device is selected in the Config menu of Easy-Setup.

Events that cause entering of suspend mode:
- Suspend mode is requested by the Fn key (Fn+ F4).
- The LCD is closed.
- The keyboard is opened.
- The specified time has elapsed from the last operation with the keyboard, mouse, hard disk drive, parallel connector, diskette drive, or the AC Adapter is plugged in. The time is specified by Suspend Timer in the ThinkPad Features program.
- The battery condition is low. The battery power indicator blinks (orange).
- The PS2 OFF command is set in the ThinkPad Features program.

Events that cause exiting or resuming of suspend mode:
- (Resume) The LCD is opened.
- (Resume) The keyboard is closed.
- (Resume) Real time clock alarm signaled.
- (Resume) Ring indicator (RI) signaled by serial or PCMCIA device.
- (Resume) The Fn key is pressed.
- (Exit) Timer conditions are satisfied to enter hibernation mode.

Hibernation Mode:
When in hibernation mode, the following occurs:
The system status, RAM, VRAM, and setup data are stored on the hard disk. The system is powered-off.

The computer cannot enter hibernation mode when:
A serial mouse or other pointing device is selected in the Config menu. The computer is powered with ac power and one of the following IBM PC cards is used.
- PCMCIA Data/FAX Modem
- High Speed PCMCIA Data/FAX Modem
- 3270 Emulation Credit Card Adapter
- 5250 Emulation Credit Card Adapter
- Token-Ring 16/4 Credit Card Adapter
- Credit Card Adapter for Ethernet

Events that cause entering of hibernation mode:
- The hibernation mode is requested by the Fn key (Fn+ F12).
- Timer conditions are satisfied in suspend mode.
- Critical low battery condition.

Event that causes exiting of hibernation mode.

The power-on switch is operated.

When power is turned on, the hibernation history of the boot record on the hard disk is recognized and system status is restored from the hard disk to resume operation.

Port Replicator Power Overload:
If power shut downs occur intermittently when using PCMCIA-2 devices via a port replicator, suspect an over-current problem. Some PCMCIA devices use more power; if the maximum usage of each device occurs simultaneously, the total current will exceed the limit, thereby causing a power shut down. Isolate this problem by removing one of the devices, and use the computer under the same condition to see whether a power shut down occurs. Do this procedure for all devices, then deter- mine the cause. Use of the larger AC Adapter (50W, optional) is recommended, if one is not yet in use.

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	Hint Category	Hardware Maintenance Information
	Date Created	04-11-96
	Last Updated	29-04-99
	Revision Date	06-05-2000
	Brand	IBM ThinkPad
	Product Family	ThinkPad 355, ThinkPad 360, ThinkPad 370, ThinkPad 750, ThinkPad 755C/CS
	Machine Type	2619, 2620, 9545
	Model	All
	TypeModel
	Retain Tip (if applicable)	N/A
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