Lenovo 90AT Hardware Maintenance Manual page 90

CAUTION:
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 removing the computer cover.
To replace the microprocessor, do the following:
1. Turn off the computer and disconnect all power cords from electrical outlets.
2. Remove the computer cover. See "Removing the computer cover" on page 74.
3. Lay the computer on its side for easier access to the system board.
4. Remove the heat sink and fan assembly. See "Replacing the heat sink and fan assembly" on page 84.
Note: Place the heat sink and fan assembly on its side so that the thermal grease on the bottom of it
does not get in contact with anything.
5. Lift the small handle
Figure 22. Accessing the microprocessor
6. Lift the microprocessor straight up and out of the microprocessor socket.
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Lenovo Hardware Maintenance Manual
1 and open the retainer 2 to access the microprocessor 3 .