Lenovo 7099U1U, Hardware Maintenance Manual

Page: 122 / 224

Replacing the power supply assembly
Attention
Do not open your computer or attempt any repair before reading and understanding the “Important safety information”
in the
ThinkCentre Safety and Warranty Guide that came with your computer. To obtain a copy of the ThinkCentre
Safety and Warranty Guide , go to:
http://www.lenovo.com/support
This section provides instructions on how to replace the power supply assembly.
Although there are no moving parts in your computer after the power cord has been disconnected, the
following warnings are required for your safety and proper Underwriters Laboratories (UL) certification.
DANGER
Hazardous moving parts. Keep fingers and other body parts away.
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 101.
3. Remove the front bezel. See “Removing and reinstalling the front bezel” on page 102.
4. Pivot the drive bay assembly upward, remove the four screws that secure the heat sink fan duct, and
then lift the heat sink fan duct up to remove it from the chassis.
116
ThinkCentre Hardware Maintenance Manual