Lenovo ThinkPad X390, Hardware Maintenance Manual, Page: 41 / 108

Power management
Sleep mode
When the computer enters sleep mode, the following events occur in addition to what occurs in screen blank
mode:
• The LCD is powered off.
• The storage drive is powered off.
• The microprocessor stops.
To put your computer into sleep mode, do the following:
• For Windows 7 : Open the Start menu, then click the arrow next to the Shut down button. Click Sleep
from the menu displayed.
• For Windows 10: Open the Start menu, click Power , and then click Sleep .
In certain circumstances, the computer goes into sleep mode automatically:
• After a period of inactivity specified in power plan settings
• When the battery power is low
To cause the computer to return from sleep mode and resume operation, do one of the following:
• Press the Fn key.
• Press the power button.
Also, in either of the following events, the computer automatically returns from sleep mode and resumes
operation:
• The ring indicator (RI) is signaled by a serial device or a PC Card device.
• The time set on the resume timer elapses.
Note: The computer does not accept any input immediately after it enters sleep mode. Wait a few
seconds before taking any action to reenter operation mode.
Hibernation mode
In hibernation mode, the following occurs:
• The system status, RAM, VRAM, and setup data are stored on the storage drive.
• The system is powered off.
Note: If the computer enters the hibernation mode while it is docked to the docking station or the port
replicator, 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.
If you 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.
Also, the computer goes into hibernation mode automatically after a period of inactivity specified in power
plan settings.
Chapter 4
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Related service information
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