78 Replacing and Adding Internal Devices
Replacing the system board
The system board is the heart of the computer, which integrates the other
elements of the system, such as the processor, memory, storage, networking,
and communications, and lets them operate in a coordinated and useful way.

To replace the system board:

1Turn off the system and disconnect the power cord and all external
peripheral devices.
2Open the case. (See “Opening the case” on page 23 and “Preventing static
electricity discharge” on page 22.)
3Place the chassis gently on its right side.
4Remove all expansion cards from the system (see “Replacing an
expansion card” on page 61.)
5Remove the back panel fan (see “Replacing the back panel and hot-plug
cage fans” on page 72.)
6Disconnect all cables from the system board, including the power cables
from the power supply. Note where the cables are connected.
Important All references to front, rear, left, or right on the computer
are based on the computer being in a normal, upright
position, as viewed from the front.
8505945.book Page 78 Thursday, March 9, 2000 2:13 PM