Lenovo 4485 Computer Hardware User Manual


 
Replacing the system board
Attention:
Do not open your computer or attempt any repair before reading and understanding the “Important safety information”
in the ThinkCentre User Guide. To obtain a copy of the ThinkCentre User Guide, go to:
http://www.lenovo.com/ThinkCentreUserGuides
This section provides instructions on how to replace the system board.
CAUTION:
The heat sink and microprocessor might be very hot. Turn off the computer and wait three to ve
minutes to let the computer cool before opening the computer cover.
To replace the system board, do the following:
1. Remove all media from the drives and turn off all attached devices and the computer. Then, disconnect
all power cords from electrical outlets and disconnect all cables that are connected to the computer.
2. Remove the computer cover. See “Removing the computer cover” on page 79.
3. Lay the computer on its side for easier access to the system board.
4. Remove the hard disk drive from the chassis. See “Replacing the primary hard disk drive” on page
103
. Remove the secondary hard disk drive if your model has one. See “Replacing the secondary
hard disk drive” on page 105.
5. Remove all memory modules and PCI cards that are currently installed. See “Installing or replacing a
memory module” on page 84 and “Installing or replacing a PCI card” on page 81.
6. Carefully take note of the location of all cable connections on the system board and disconnect all the
cables. See “Locating parts on the system board” on page 77.
7. Remove the heat sink and fan assembly from the failing system board. See “Replacing the heat sink and
fan assembly” on page 95.
8. Remove the eight screws that secure the system board.
100 ThinkCentre Hardware Maintenance Manual