Dell Precision M20 - Manual (Page 4)

The green lights located above the keyboard indicate the following:
Left View
PC Card slot — Supports one PC Card, such as a modem or network adapter. The computer ships with a plastic blank installed in the slot. For more
information, see " Using PC Cards ."
smart card slot — Supports one smart card. For more information, see " Using Smart Cards ."
Turns on when the numeric keypad is enabled.
Turns on when wireless devices are enabled.
Turns on when the uppercase letter function is enabled.
Turns on when Bluetooth® wireless technology is enabled. To enable or disable Bluetooth wireless technology, press <Fn><F2>.
NOTE: Bluetooth wireless technology is an optional feature on your computer, so the icon turns on only if you ordered Bluetooth wireless
technology with your computer. For more information, see the documentation that came with your Bluetooth wireless technology.
Turns on when the scroll lock function is enabled.
1 security cable slot 4 PC Card slot
2 audio connectors (2) 5 smart card slot
3 infrared sensor
NOTE: The computer turns on the fan when the computer gets hot. Fan noise is normal and does not indicate a problem with the fans or the computer.
CAUTION: Do not block, push objects into, or allow dust to accumulate in the air vents. Do not store your Dell™ computer in a low -airflow
environment, such as a closed briefcase, while it is running. Restricting the airflow can damage the computer or cause a fire.