Preparing to upgrade 7-5
Opening the system unit
Each time you open your system unit, you must follow specific safety procedures to
ensure that you do not damage your computer.

Taking safety precautions

Before you open the system unit, review “Safety informa tion” on page xiii.
For your safety and the safety of your equipment, follow these steps before you
remove the system unit cover:
1. If your computer is on or in any of the power-saving modes, shut down the
computer.
2. Turn off the computer and any attached devices that have their own power
switches.
3. Unplug all power cables from electrical outlets.
4. Disconnect all communication cables (such as modem or network cables)
from communication outlets.
5. Disconnect all cables and cords from the computer; this includes power
cords, signal cables from external devices, communication cables, and any
other cables attached to the computer.
6. Proceed to the next section for instructions on removing the cover.