Lenovo ThinkCentre 0900 User Manual page 65

CAUTION:
Never remove the cover on a power supply or any part that has the following label attached.
Hazardous voltage, current, and energy levels are present inside any component that has this label
attached. There are no serviceable parts inside these components. If you suspect a problem with
one of these parts, contact a service technician.
To replace the power supply assembly, do the following:
1. Remove all media from the drives and turn off all attached devices and the computer. Then, disconnect
all power cords from electrical outlets and disconnect all cables that are connected to the computer.
2. Remove the computer cover. See "Removing the computer cover" on page 34.
3. Remove the front bezel. See "Removing and reinstalling the front bezel" on page 34.
4. Pivot the drive bay assembly upward. Then, pivot the two plastic retaining clips outward to remove
the heat sink fan duct from the failing heat sink and fan assembly.
Figure 35. Removing the heat sink fan duct
5. Disconnect the power supply assembly cables from all drives and from the 24-pin power connector and
4-pin power connector on the system board. See "Locating parts on the system board" on page 13.
Note: You might also need to release the power supply assembly cables from some cable clips or ties
that secure the cables to the chassis. Make sure that you note the cable routing before disconnecting
the cables.
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Chapter 5 Installing or replacing hardware
53