Hi Myles,

It's likely that a new power supply unit will require some sort of cabling adjustments to fit the computer's hardware configuration. However, that's not too difficult to achieve utilizing adapters and extensions.

Unless, of course, you happen to come across one specifically designed for your particular computer. Here's a site which lists lots of PSUs for different eMachines models: http://www.atxpowersupplies.com/emachine-power-supplies.php. Unfortunately, your particular model doesn't appear to be listed but you may find something close.