System Board And Coin-Cell Battery - Lenovo ThinkCentre M90n-1 Hardware Maintenance Manual

System board and coin-cell battery

Prerequisite
Before you start, read Chapter 1 "Important safety information" on page 1 and print the following
instructions.
Avoid contact with the hot computer. During operation, the computer becomes hot enough to burn the skin.
Before you touch the computer, turn off the computer, disconnect power, and wait approximately 30 minutes
for the computer to cool.
Replacement procedure
1. Remove the bottom cover. See "Bottom cover" on page 67.
2. Remove the M.2 solid-state drives. See "M.2 solid-state drives" on page 69.
3. Remove the Wi-Fi card. See "Wi-Fi card" on page 70.
4. Remove the wireless WAN card. See "Wireless WAN card" on page 71.
5. Record the cable routing and cable connections, and then disconnect all cables from the system board.
See "System board" on page 54.
6. Remove the system board.
Note: Carefully handle the system board by its edges.
7. Turn over the system board so that the coin-cell battery is facing up.
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M90n-1 Hardware Maintenance Manual