To replace the microprocessor, do the following:

Important: The heat sink and microprocessor might be very hot. Make sure these components are cool enough to safely handle before continuing this procedure.

1. Remove the cover. See "Cover removal".
2. Lift the fan duct off the heat sink fan.
3. Disconnect the heat sink and fan assembly cable from the system board. See the system board illustration for your machine type at "System board connectors".
4. Remove the four screws securing the heat sink and fan assembly to the system board

5. Lift the heat sink and fan assembly off the system board. Place the heat sink on its side so that the thermal grease does not come in contact with anything.
   
   Note: You might have to gently twist the heat sink to free it from the microprocessor.

6. To remove the microprocessor 2 from the system board, lift the small handle 3 and open the retainer 1.

Important: Touch only the sides of the microprocessor. Do not touch the gold contacts on the bottom.

7. Lift the microprocessor straight up and out of the socket.

Notes:

1. Note the orientation of the notches 1 on the microprocessor. This is important when reinstalling the microprocessor on the system board.

2. Do not drop anything onto the microprocessor socket while it is exposed. The socket pins must be kept as clean as possible.

8. Make sure that the microprocessor retainer is fully open.
9. Holding the microprocessor with your fingers, remove the protective cover 2 that protects the gold contacts on the new microprocessor 1.

10. Holding the microprocessor with your fingers, align the notches on the microprocessor with the tabs in the microprocessor socket.
11. Lower the microprocessor straight down into the socket.

12. To secure the microprocessor in the socket, close the microprocessor retainer and lock it into position with the small handle.
13. Use the thermal grease syringe to place five drops of grease on the top of the microprocessor. Each drop of grease should be 0.03ml (3 tick marks on the grease syringe).

1. Install the heat sink and fan assembly on the system board.
2. Connect the heat sink and fan assembly cable to the system board. See the system board illustration for your machine type at "System board connectors".
3. Position the fan duct on the heat sink fan.
4. Go to "Completing the parts replacement".