by Bob Pritchard

Created on: October 27, 2010   Last Updated: April 22, 2011

A computers power supply unit is an important component solely responsible for delivering all the necessary power to the entire computer. If you find you need to replace your power supply you can likely do it yourself. While this would seem like a difficult component to replace it is a relatively simple operation. Most power supplies today are modular, meaning rather than having to soldering the wiring they are all plug in units.

Before buying a replacement power supply you need to take a look at the components in your computer. There is a possibility that your power supply unit was not quite large enough to handle the current draw of the components that make up your computer. This is especially true if you built your own computer. To determine the right size you need to know what each component in your computer draws. This sounds like a rather daunting job but with the use of this online calculator http://www.vbutils.com/power.asp you can find your total current draw very easily. To use the calculator you do need to make a list of the components that make up your computer although you don't need an in depth list with model and serial numbers. A basic list will be fine. If that isn't possible you can replace your power supply by getting the same unit. It is however a good idea to get a unit that can handle slightly more wattage that the one your replacing. Again being slightly undersized may be the reason it failed.

To find a replacement for your current power supply you can use this handy reference. http://www.atxpowersupplies.com/power-supply-cross-r eference.php Here you only need brand and model numbers to find a compatible replacement.

The actual job of replacing your computers power supply is straight forward. What I find helpful is to take a couple pictures of the inside of the computer prior to disconnecting anything. This way if you can't seem to find where a certain connection goes the picture will show you. Don't remove the bad supply until you have the replacement. This makes it much easier to find where the connections go being you just unplugged them. To start the replacement disconnect the main power cord then unplug all the connectors taking note where they came from. Remove the old supply and mount the new. Now it's only a matter of reconnecting the plugs. Just be careful not to let any of the wiring get into any of the cooling fans. It's a good idea to add wire ties to keep the wires neat.

In most cases changing the power supply will put you back in business but there is a small chance that when the power supply failed it damaged the motherboard. There is no way to tell if the motherboard has failed without changing the power supply but in the majority of cases the supply is the only failure.

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