System board
Description Spare part number
System board for use in computer models equipped with discrete graphics subsystems (includes
thermal material)
486725-001
System board for use in computer models equipped with UMA graphics subsystems (includes
thermal material)
486726-001
System board for use only in computer models with AMD processors (includes thermal material) 492256-001
When replacing the system board, be sure that the following components are removed from the defective
system board and installed on the replacement system board:
●RTC battery (see RTC battery on page 52)
●Memory modules (see Memory module on page 54)
●WLAN module (see WLAN module on page 49)
●Modem module (see Modem module on page 76)
Before removing the system board, follow these steps:
1. Shut down 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 all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and
then unplugging the AC adapter from the computer.
4. Remove the battery (see Battery on page 43).
5. Remove the following components:
a. Hard drive (see Hard drive on page 46)
b. Optical drive (see Optical drive on page 44)
c. Keyboard (see Keyboard on page 56)
d. Switch cover (see Switch cover on page 58)
e. Speaker assembly (see Speaker assembly on page 60)
f. Display assembly (see Display assembly on page 62)
g. Top cover (see Top cover on page 69)
Remove the system board:
1. Turn the computer upright with the right side toward you.
82 Chapter 4 Removal and replacement procedures