Lenovo 2491 Laptop User Manual


 
16. Reconnect all cables that were disconnected from the system board.
17. Go to “Completing the parts replacement” on page 98.
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. Open the computer cover. See “Opening the computer cover” on page 72.
3. Take notes of the location of all the cable connectors on the system board and then disconnect all the
cables. See “Locating parts on the system board” on page 71.
4. Remove the heat sink from the system board. See “Replacing the heat sink” on page 81.
5. Remove the memory modules from the failing system board. See “Installing or replacing a memory
module” on page 74
.
6. Remove the PCI card from the failing system board. See “Installing or replacing the PCI card” on
page 75.
7. Remove the battery from the failing system board. See “Replacing the battery” on page 80.
8. Remove the microprocessor from the failing system board. See “Replacing the microprocessor” on
page 82
.
9. Remove the four screws that secure the failing system board to the protective cover.
86 ThinkCentre Hardware Maintenance Manual