Lenovo ThinkCentre M75n Hardware Maintenance Manual page 115

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. Turn over the computer so that the bottom cover is facing up.
2. Remove the bottom cover. See "Bottom cover" on page 97.
3. Remove the M.2 solid-state drives. See "M.2 solid-state drives" on page 100.
4. Remove the Wi-Fi card. See "Wi-Fi card" on page 98.
5. Remove the system board. See "System board and coin-cell battery" on page 101.
6. Remove the left cover. See "Left cover and front antenna cable" on page 103.
7. Remove the right cover. See "Right cover" on page 105.
8. Remove the internal speaker. See "Internal speaker" on page 106.
9. Remove the rear antenna cable. See "Rear antenna cable" on page 107.
10. Remove the heat sink.
11. Install the heat sink.
12. Reinstall all removed parts. Turn over the computer so that the bottom cover is facing down. Then,
reconnect the power adapter and all disconnected cables to the computer.
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Chapter 6 Hardware removal and installation
109