Status Indicators - Lenovo ThinkPad T420 User Manual

4 Fan louvers (rear)
The internal fan and louvers enable air to circulate in the computer and cool the central processor.
Note: To avoid impeding airflow, do not place any obstacle in front of the fan.

Status indicators

The status indicators show the current status of your computer.
System-status indicators
1 Device Access
A hard disk drive or an optional drive, such as a drive in the Ultrabay, is being used to read or write data.
When this indicator is blinking, do not put the computer into sleep (standby) mode, remove the
device from the bay, or turn off the computer.
2 Power On
The power switch stays lit whenever the computer is on, blinks when the computer is in sleep (standby)
mode, and is off when the computer is off.
3 Caps Lock
Caps Lock mode is enabled. You can enter all alphabetic characters (A-Z) in upper case without pressing
the Shift key.
4 Numeric lock
By default, when the numeric lock is on, the numeric lock indicator is displayed on the screen. To change the
settings of the numeric lock indicator, see "Changing display settings" on page 69.
Note: Another mode available for your computer, though there is no indicator for it, is Scroll Lock mode.
When this mode is enabled, the arrow keys can be used as function keys for screen-scrolling, but not for
.
Chapter 1 Product Overview
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