Lenovo 70LY User Manual And Hardware Maintenance Manual page 122

Figure 98. Removing the CPU socket cover
9. Remove the CPU from the old system board and install it on the new system board. See "CPU" on page
101.
10. Use a cleaning pad to wipe the thermal grease from the heat sink and the top of the CPU. Dispose of the
cleaning pad after all of the thermal grease is removed.
11. Use one of the following methods to apply appropriate amount of thermal grease to the top of the CPU
in the shape of a cross or a circle as shown. Using too much or too little thermal grease can cause a
thermal problem due to imperfect contact with the components.
Notes:
• Do not touch the thermal grease.
• Keep the thermal grease off the system board.
Figure 99. Applying the thermal grease to the top of the CPU
12. Install the heat sink and fan assembly on the new system board. See "Installing the heat sink and fan
assembly" on page 91.
13. Reinstall all parts that you have removed one by one in the reversed sequence as you remove them.
Connect all cables to the new system board.
14. Return the old system board. The old system board must be returned with a CPU socket cover to
protect the pins on the CPU socket during shipping and handling. Use the CPU socket cover removed
from the new system board.
To install a CPU socket cover on the old system board, do the following:
a. After you have removed the CPU from the old system board, close the CPU retainer, press down the
small handle, and then push the handle inward to lock the retainer into position.
b. Note the orientation of the socket cover, and install one side of the socket cover into the CPU socket.
Then, carefully press the other side of the socket cover downward until it snaps into position.
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ThinkServer TS450 User Guide and Hardware Maintenance Manual