Lenovo T420 Maintenance Manual page 58

Table 7. Status indicators
Indicator
Speaker mute
1
Microphone mute
2
Wireless LAN, Wireless WAN,
3
or WiMAX status
Bluetooth wireless or Wireless
4
USB status
R
Device access
5
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ThinkPad T420 and T420i Hardware Maintenance Manual
Meaning
Orange:
The speaker is on mute. To set the speakers on mute or unmute,
press the speaker mute button.
Orange:
The microphone is on mute. None of the recording devices is
available while the microphone mute is on by default.
Green:
The wireless LAN feature (the IEEE 802.11 b/g standard, 802.11
a/b/g, or 802.11n), wireless WAN feature, or WiMax feature is
on, and the radio link is ready for use.
Data is being transmitted.
Green:
The Bluetooth wireless feature is on, and the radio link is ready
for use.
Data is being transmitted.
Green:
Data is being read from or written to the hard disk drive, the
diskette drive, or the drive in the Serial Ultrabay Enhanced
device. When this indicator is on, do not put the computer into
sleep (standby) mode or turn off the computer.
Note: Do not move the system while the green device access light is on.
Sudden physical shock could cause drive errors.