Lenovo ThinkCentre A58 User Manual - Page 106

8. Alternate tightening each screw a small and equal amount until the heat sink and fan assembly is secured to the system board. Do not over-tighten the screws. 9. Connect the new heat sink and fan assembly cable to the microprocessor fan connector on the system board. What to do next: v To work with another piece of hardware, go to the appropriate section. v To complete the replacement, go to "Completing the FRU replacement" on page 120. Replacing the microprocessor Attention Do not open your computer or attempt any repair before reading and understanding the "Important safety information" in the ThinkCentre Safety and Warranty Guide that came with your computer. To obtain a copy of the ThinkCentre Safety and Warranty Guide, go to: http://www.lenovo.com/support This section provides instructions on how to replace the microprocessor. 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. Remove the computer cover. See "Removing the computer cover" on page 86. 2. Lay the computer on its side for easier access to the system board. 3. Remove any parts or cables that may prevent your access to the system board. 4. Disconnect the heat sink and fan assembly cable from the microprocessor fan connector on the system board. See "Locating parts on the system board" on page 89. 5. Remove the heat sink and fan assembly. See "Replacing the heat sink and fan assembly" on page 98. 6. Place the heat sink and fan assembly on its side so that the thermal grease does not come in contact with anything. 100 Hardware Maintenance Manual