2–6 Maintenance and Service Guide
External component identification
Front components
Rear components
Item Component Description
1Power lig ht ■On: The computer is on.
■Blinking: The computer is in the Sleep state.
■Off: The computer is off or in Hibernation.
2Battery light ■On: A battery is charging.
■Blinking: A battery that is the only available power source has
reached a low battery level. When the battery reaches a critical
battery level, the battery light begins blinking rapidly.
■Off: If the computer is plugged into an external power source,
the light is turned off when all batteries in the computer are
fully charged. If the computer is not plugged into an external
power source, the light stays off until the battery reaches a low
battery level.
3Drive light Blinking: The hard drive or optical drive is being accessed.
4Audio-in (microphone) jack Connects an optional computer headset microphone, stereo array
microphone, or monaural microphone.
5Audio-out (headphone) jack Produces sound when connected to optional powered stereo
speakers, headphones, ear buds, a headset, or television audio.
Component Function
Vents (2) Enable airflow to cool internal components.
✎The computer fan starts up automatically to cool
internal components and prevent overheating. It is
normal for the internal fan to cycle on and off
during routine operation.