by Paul Sanders
Upgrading components on your desktop computer, and doing it yourself, can be very rewarding. If you are upgrading components that use up a lot of power, like a video card, you may need to install a new power supply to handle the load. Most computer power supplies will list its maximum wattage. You may need to calculate your computer's power usage by adding up the maximum power usage of all your components. That number will be your guide when searching for the right computer power supply. Certain computer cases will only accept compatible power supplies. You can determine which type of case you have by examining the motherboard for an information tag. When you're ready to install your computer power supply, use these simple steps to help you along.
Prepare your computer. Avoid damaging your computer with static electricity by installing the computer power supply in a non-carpeted area, and touch an unpainted metal surface to discharge static from your body. You'll need to remove current computer power supply before installing the new one. Unplug all the cords from your computer tower and open the computer case. For some cases, you may need to remove the back panel as well to reach the computer power supply.
Disconnect the power supply from each component. You'll find several "leads" connecting the old computer power supply to the motherboard, hard drive, video cards and other components. Before disconnecting them, take note of where each one connects and label each lead on the new power supply with some masking tape. Keeping track of the leads will make installing the new power supply much easier.
Remove the mounting screws and the power supply. There will be four mounting screws on the back panel of the computer tower which hold the computer power supply in place. Remove them and slide the old power supply out, taking care not to drop it or damage the motherboard.
Place the new computer power supply. Slip your new computer power supply in to replace the old one. Secure the power supply with the mounting screws and connect the leads to the motherboard using according to the notes you made in Step 2. If your computer power supply has extra leads left over, tie them off, or tape them to the side of the computer case so they won't fall into a fan or other components.
Test the new power supply. Before replacing the case cover, plug the power cord into the power supply and connect the monitor, mouse and keyboard. Turn the computer on and make sure that your computer boots properly. If everything works fine, you've installed the computer power supply correctly and you can replace the case cover.
If you computer doesn't boot properly, consult the user manual for your computer, motherboard and computer power supply for troubleshooting tips to diagnose the problem.