When Working Inside Your Computer

•To avoid possible damage to the system board, wait 10 to 30 seconds after disconnecting the computer from AC power before disconnecting a peripheral or removing a component.

•To help prevent electric shock, plug the computer and peripheral power cables into properly grounded power sources. These cables are equipped with three-prong plugs to help ensure proper grounding. Do not use adapter plugs or remove the grounding prong from a cable. If you must use an extension cable, use a three-wire cable with properly grounded plugs.

•To help protect your computer system from sudden, transient increases and decreases in electrical power, use a surge suppressor, line conditioner, or uninterruptible power supply (UPS).

•Be sure that nothing rests on your computer system’s cables and that the cables are not located where they can be stepped on or tripped over.

•Do not spill food or liquids on your computer. If the computer gets wet, consult your Diagnostics and Troubleshooting Guide or System User’s Guide.

•Do not push any objects into the openings of your computer. Doing so can cause fire or electric shock by shorting out interior components.

•Keep your computer away from radiators and heat sources. Also, do not block cooling vents. Avoid placing loose papers underneath your computer; do not place your computer in a closed-in wall unit or on a bed, sofa, or rug.

Before you remove the computer cover, perform the following steps in the sequence indicated.

CAUTION: Do not attempt to service the computer system yourself, except as explained in this guide and elsewhere in Dell documentation. Always follow installation and service instructions closely.

NOTICE: To help avoid possible damage to the system board, wait 10 to

30 seconds after turning off the system before removing a component from the system board or disconnecting a peripheral device from the computer.

1.Turn off your computer and any peripherals.

2.Ground yourself by touching an unpainted metal surface on the chassis, such as the metal around the card-slot openings at the back of the computer, before touching anything inside your computer.

While you work, periodically touch an unpainted metal surface on the computer chassis to dissipate any static electricity that might harm internal components.

3.Disconnect your computer and peripherals from their power sources. Also, disconnect any telephone or telecommunication lines from the computer.

Doing so reduces the potential for personal injury or shock.

2-2 Dell Precision WorkStations Safety and Regulatory Information