Lenovo ThinkPad T420 Hardware Maintenance Manual page 58

Table 7. Status indicators (continued)
Indicator
Sleep (standby for Windows
11
XP) status
52
ThinkPad T420 and T420i Hardware Maintenance Manual
Meaning
The ac power adapter is attached to the computer.
The battery status indicator is off:
The battery pack of the computer is fully charged or detached.
Green:
The computer is in sleep (standby) mode.
Blinking green:
The computer is entering sleep (standby) mode or hibernation
mode, or is resuming normal operation.