Replacing the system board - ThinkCentre M81 (type 0268, 1730, 4166, 4169, 5030, 5048, 5069, 7517)
Do not open your computer or attempt any repair before reading and understanding the "Important safety information" in the ThinkCentre Safety and Warranty Guide that came with your computer. To obtain a copy of the ThinkCentre Safety and Warranty Guide, go to:http://www.lenovo.com/support
This section provides instructions on how to replace the system board.
The heat sink and microprocessor might be very hot. Turn off the computer and wait three to five minutes to let the computer cool before opening the computer cover.
To replace the system board, do the following:
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.
Install the new system board into the chassis by aligning the eight mounting studs in the chassis with the corresponding holes in the new system board. Carefully slide the new system board into the chassis until it is secured in place by the mounting studs. Then, install the eight screws to secure the system board.