The power supply provides the power for all of the components of a personal computer. When replacing a power supply, it is important to consider the power needs of the internal components of the system, as well as, any non-powered peripheral devices used with the system.

When determining the type of power supply unit (PSU) needed to run your computer and all of its components, there are certain factors to keep in mind:

• Maximum Output - This is the number of watts the power supply is capable of delivering. The higher the wattage, the more power available. By determining the amount of wattage you need to run a computer, you could avoid spending more money than necessary on the power supply.
• Efficiency Rating - This determines how much energy your power supply uses to deliver the necessary wattage to run your computer. Most power supplies have an efficiency rating of 70 percent (%) or higher at full load.
• Cooling - The more wattage there is, the more heat produced. The power supply should have at least one 80mm fan to cool the system. Power supplies with over 400 watts should have two 80mm fans or one 120mm fan to effectively cool the machine.
• Power Connectors - Make sure the power supply comes with enough power connectors to run your computer.

Identify the specifications you would need to gather to select an appropriate power supply for a system.

Include the components that you would need to use for gathering the wattage requirements for a system.

List the steps for selecting and replacing a power supply in a desktop computer that will require a minimum of 1,200 watts of power. Include the choice of a power supply that meets the needs of the system, the steps for transferring the power supply to the new system, and any cautions or notes needed. The target audience for your procedure will be the help desk support agent, so the process should be clear, concise, and complete.