Hardware Reference Guide
3 Hardware repair and upgrade
Warnings and cautions
Before performing upgrades be sure to carefully read all of the applicable instructions, cautions, and
warnings in this guide.
WARNING! To reduce the risk of personal injury from electrical shock, hot surfaces, or re:
Disconnect the power cord from the AC outlet before removing the enclosure. Energized parts are inside.
Allow the internal system components to cool before you touch them.
Replace and secure the enclosure before restoring power to the equipment.
Do not connect telecommunications or telephone connectors to the network interface controller (NIC)
receptacles.
Do not disable the power cord grounding plug. The grounding plug is an important safety feature.
Plug the power cord in a grounded (earthed) AC outlet that is easily accessible at all times.
If the power cord has a 3-pin attachment plug, plug the cord into a grounded (earthed) 3-pin outlet.
Disconnect power from the computer by unplugging the power cord from the AC outlet. When unplugging the
power cord from the AC outlet, grasp the cord by the plug.
For your safety, do not place anything on power cords or cables. Arrange them so that no one may
accidentally step on or trip over them. Do not pull on a cord or cable.
To reduce the risk of serious injury, read the Safety & Comfort Guide provided with your user guides. It
describes proper workstation setup and proper posture, health, and work habits for computer users. The
Safety & Comfort Guide also provides important electrical and mechanical safety information. The Safety &
Comfort Guide is also available on the Web at http://www.hp.com/ergo.
IMPORTANT: Static electricity can damage the electrical components of the computer or optional
equipment. Before beginning these procedures, ensure that you are discharged of static electricity by briey
touching a grounded metal object. See Electrostatic discharge on page 38 for more information.
When the computer is plugged into an AC power source, voltage is always applied to the system board. You
must disconnect the power cord from the power source before opening the computer to prevent damage to
internal components.
Additional information
For more information about removing and replacing hardware components, the BIOS (F10) Setup utility, and
troubleshooting, refer to the Maintenance and Service Guide (available in English only) for your computer
model at http://www.hp.com/support.
26 Chapter 3 Hardware repair and upgrade