HP ProOne 400 G1 All-in-One Hardware Reference Manual page 34

NOTE: The lifetime of the lithium battery can be extended by plugging the computer into a live AC
wall socket. The lithium battery is only used when the computer is NOT connected to AC power.
HP encourages customers to recycle used electronic hardware, HP original print cartridges, and
rechargeable batteries. For more information about recycling programs, go to
recycle.
1. Remove all removable media, such as optical discs or USB flash drives, from the computer.
2. Turn off the computer properly through the operating system, then turn off any external devices.
3. Disconnect the power cord from the power outlet and disconnect any external devices.
CAUTION:
as long as the system is plugged into an active AC outlet. You must disconnect the power cord
to avoid damage to the internal components of the computer.
4. Remove/disengage any security devices that prohibit opening the computer.
5. Place the computer face down on a soft flat surface. HP recommends that you set down a
blanket, towel, or other soft cloth to protect the bezel and screen surface from scratches or other
damage.
6. Loosen the two captive screws at the bottom of the computer (1) to release the bottom edge of
the access panel.
7. Rotate the bottom edge of the access panel up (2), and then lift the access panel off of the
computer (3).
Figure 3-20
28 Chapter 3 Hardware repair and upgrade
Regardless of the power-on state, voltage is always present on the system board
Removing the access panel
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