Lenovo ThinkCentre Edge 91 Hardware Maintenance Manual page 141

8. Remove the eight screws that secure the system board.
Figure 71. Removing the eight screws that secure the system board
9. Lift the system board out of the chassis.
10. Remove the microprocessor from the failing system board and install it on the new system board. See
"Replacing the microprocessor" on page 133.
11. Install the new system board into the chassis by aligning the eight mounting studs in the chassis with the
corresponding holes in the new system board. Then, install the eight screws to secure the system board.
12. Install the heat sink and fan assembly and connect the heat sink and fan assembly cable to the new
system board. See "Replacing the heat sink and fan assembly" on page 130.
13. Install all memory modules and PCI cards removed from the failing system board on the new system
board. See "Installing or replacing a memory module" on page 118 and "Installing or replacing a PCI
card" on page 116.
14. Reconnect all remaining cables to the system board. See "Locating parts on the system board" on
page 109.
15. Lower the optical drive bay assembly.
16. To complete the replacement, go to "Completing the parts replacement" on page 141.
The failing system board must be returned with a microprocessor socket cover to protect the pins during
shipping and handling.
To install the microprocessor socket cover, do the following:
1. Release the lever securing the microprocessor retainer and open the retainer to access the
microprocessor.
.
Chapter 9 Replacing FRUs (Machine Types: 1857, 1893, and 1895)
137