This section provides instructions on how to replace the system board.

CAUTION:

The heat sink and fan assembly might be very hot. Turn off the computer and wait three to five minutes to let the computer cool before removing the computer cover.

Note: When replacing the system board, you must order a new retention module for the new system board. Make sure you have a retention module for the new system board before continuing this procedure.

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".
3. Lay the computer on its side for easier access to the system board.
4. Remove all memory modules and PCI cards that are currently installed. See "Installing or replacing a memory module" and "Installing or replacing a PCI card".
5. Remove the secondary hard disk drive. See "Replacing the secondary hard disk drive".
6. Remove the heat sink and fan assembly from the failing system board. See "Replacing the heat sink and fan assembly".
7. Remove the microprocessor from the failing system board. See "Replacing the microprocessor".
8. Remove the battery from the failing system board. See "Replacing the battery".
9. Note the location of all cable connections on the system board and disconnect all cables. See "Locating parts on the system board".
10. Remove the eight screws that secure the system board to the chassis, following the sequence shown in the illustration:

11. Carefully lift the failing system board out of the chassis.
12. Position the new system board into the chassis so that the screw holes in the new system board are aligned with those in the chassis. Install the screws that secure the system board following the sequence shown in figure above.
13. Remove the microprocessor socket cover from the new system board.
14. Install the memory modules, PCI cards, battery, microprocessor, and heat sink and fan assembly that you removed from the failing system board to the new system board.
15. Reinstall the secondary hard disk drive. See "Replacing the secondary hard disk drive".
16. Connect all cables to the system board. See "Locating parts on the system board".
17. To complete the replacement, go to "Completing the FRU replacement".

The failing system board must be returned with a microprocessor socket cover to protect the pins during shipping and handling.

To install the microprocessor socket cover:

1. Remove the microprocessor from the microprocessor socket. See "Replacing the microprocessor".
2. Align the notches (1) on the microprocessor socket cover with the alignment keys (2) in the microprocessor socket.
3. Install one side of the socket cover into the microprocessor socket as shown.

Note: Your microprocessor socket and socket cover might look slightly different from the illustration.

4. Carefully press the other side of the socket cover downward until the socket cover snaps into place.

5. Carefully check the corners of the socket cover to make sure that the cover is secured in the microprocessor socket.
6. Lower the microprocessor retainer and then lower the lever to secure the retainer. Make sure the lever is locked into position.