This is an effort to answer some of the most frequently asked questions about eMachine PSUs.


How do if I know if my PSU bad?

If it's dead as a hammer you can probably find out with your trusty $500 Fluke meter or a $20 PSU tester.
If it's marginal or you're having intermittent problems, the best way to check it is with a KNOWN GOOD one.

What form factor PSU do I need?

If you open up that eMachine case you either going to be looking at an ATX PSU or microATX style. The first thing you need to do is identify what form factor PSU you have. You can do this HERE

If you have an older eMachine with a Fiat, Lantra, Verna or Big Bear case, you will need a microATX: Dimensions: 5x3x4", HxWxD. Use 3 mounting screws.

All of the Nexgen and eCooper cases use an ATX style.
ATX Dimensions: 6x3.5x5.5", HxWxD. Uses 4 mounting screws.

Note: Although the ATX is an industry standard, the depth (front to back) measurement can vary and you could run into interference between the PSU and your optical drive. See pics below:

How many watts do I need?

You tell us. Do you have a handful of No.2 pencils holding together 6 hard drives? Pay more for that kick@ss video card than you did the whole system? Got all the RAM slots filled up?
HERE is a good guide to help determine your needs.

Will too many watts fry my system?

There is no such thing as too many watts. Your system is only going to "pull" as much power as it needs,,,it doesn't get "pushed".
Get the highest rated you can afford and the biggest that your case will hold without interference.

What's the best brand?

Everybody has their likes and dislikes but as a rule of thumb, the heavier the better. The weight of a power supply is directly related to the quantity, quality, and size of the material (thus cost) used to build the power supply. This still is no guarantee of reliability.

How do I physically replace the PSU?

There are download-able PDF files HERE (see Step-By-Step Instructions on how to gain entry into the case) that has illustrations and instructions on how to replace the PSU.

Do I really need to upgrade my PSU?

If you own an eMachine, YES. They are generally the weakest link in your system and should be the FIRST item on your upgrade list!