Reverse this procedure to install the WLAN module.
Fan
Description Spare part number
Fan (includes cable) 740149-001
NOTE: To properly ventilate the computer, allow at least 7.6 cm (3 in) of clearance on the rear edge
of the computer. The computer uses an electric fan for ventilation. The fan is controlled by a
temperature sensor and is designed to turn on automatically when high temperature conditions exist.
These conditions are affected by high external temperatures, system power consumption, power
management/battery conservation configurations, battery fast charging, and software requirements.
Exhaust air is displaced through the ventilation grill located on the rear edge of the computer.
Before removing the fan, follow these steps:
1. Turn off the computer. If you are unsure whether the computer is off or in Hibernation, turn the
computer on, and then shut it down through the operating system.
2. Disconnect the power from the computer by unplugging the power cord from the computer.
3. Disconnect all external devices from the computer.
4. Remove the keyboard/top cover (see
Keyboard/top cover on page 23).
5. Disconnect the battery cable from the system board (see
Speakers on page 26).
Remove the fan:
1. Disconnect the fan cable from the system board.
2. Remove the three Phillips PM2.0×2.5 screws (2) that secure the fan to the base enclosure.
34 Chapter 4 Removal and replacement procedures preliminary requirements