Lenovo ThinkCentre E51 Hardware Maintenance Manual - Page 109

16. Lower the small handle to secure the microprocessor in the socket. 17. Install a new retention bracket for the heat sink by aligning the posts on the bracket with the holes in the system board and pushing the posts through the holes until the retention bracket is secure. 18. Connect the heat sink and fan assembly cable to the system board. See the system board illustration for your machine type at "Identifying parts on the system board" on page 86. 19. Install the new system board into the chassis and align the screw holes with those in the chassis. Insert and tighten the screws that secure the system board. 20. Connect all cables to the system board. See the system board illustration for your machine type at "Identifying parts on the system board" on page 86. 21. Go to "Completing the FRU replacement" on page 116. Replacing the microprocessor The procedure for replacing the microprocessor is different depending on the machine type of the computer. Machine types 8290, 8291, 8292, 8469, 8472, 8708, 8709, 8719, 8771, 8772, 8776, 8777, 8817, 9214, 9215, and 9216 Note: The new microprocessor is shipped with a new heat sink. Make sure to use the new heat sink when installing the new microprocessor. 1. Remove the left-side cover. See "Removing the covers" on page 85. 2. Place the computer on its right side to help make the microprocessor more accessible. 3. Disconnect the heat sink and fan assembly cable from the system board. See the system board illustration for your machine type at "Identifying parts on the system board" on page 86. Chapter 8. Replacing FRUs (Tower computers) 103