[ The PC Guide | Systems and Components Reference Guide | Power | The Power Supply | Parts of the Power Supply ]

Case and Cover

Every PC power supply comes surrounded by a metal case with a metal cover. The cover is normally secured with four screws and comes up off the top of the case. In many ways, the case of the power supply is to the power supply what the case of the PC is to the PC as a whole. It has several functions.

The case isolates the components inside the power supply from the rest of the PC. This serves to keep harmful electromagnetic interference inside the box, which is important because the switching design used for PC power supplies can otherwise cause emissions that will wreak havoc on other components inside and outside the PC. The case also keeps prying fingers outside the box where they will remain safely non-electrocuted. :^) Power supplies are usually intended to be considered as "black boxes" and not serviced by individual PC owners.

The design of the case and cover are also important because they play a role in cooling the power supply components, and to some extent, the whole PC. Ventilation slots or holes are placed into the case in key locations to allow the power supply fan to provide air flow over critical components.

Warning: In addition to other warnings about not opening the power supply for safety reasons that you will find on this site, another reason is that most companies will void your power supply warranty--and possibly your system warranty if you purchased a retail PC--if you open the power supply. Look for small "warranty void if removed" stickers around the perimeter of the cover.

Next: Power Cord and Power Pass-Through

Home  -  Search  -  Topics  -  Up