Absolute Beginner's Guide to A+ Certification

Avoiding Power Supply Hazards

To avoid shock and fire hazards when working with power supplies, follow these guidelines:

• Never disassemble a power supply or push metal tools through the openings in the case. Long after you shut off the system, the wire coils inside the power supply retain potentially fatal voltage levels. If you want to see the interior of a power supply safely, check the Web sites of leading power supply vendors such as PC Power and Cooling.

• If you are replacing the power supply in a Dell desktop computer, determine whether the computer uses a standard ATX or Dell proprietary ATX power supply. Many Dell computers built from ...