Lenovo ThinkCentre M90n-1 Hardware Maintenance Manual page 89

Heat sink
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. Remove the system board. See "System board and coin-cell battery" on page 74.
6. Remove the left cover. See "Left cover and front Wi-Fi antenna cable" on page 76.
7. Remove the right cover. See "Right cover and front wireless WAN antenna cable" on page 78.
8. Remove the internal speaker. See "Internal speaker" on page 81.
9. Remove the rear Wi-Fi antenna cable. See "Rear Wi-Fi antenna cable" on page 77.
10. Remove the rear wireless WAN antenna cable. See "Rear wireless WAN antenna cable" on page 80.
11. Remove the heat sink.
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Chapter 6 Hardware removal and installation
83