| | Case: All of the parts fit into a box, or "case", with bays and slots that hold system components such as the motherboard, hard drive, CD-ROM drive, floppy drive, etc. - all described below. The most popular form of case is the "tower", which stands upright to save floor or desk space. Older "desktop" cases perform the same function as tower cases, the only difference being that they lay flat and typically support a monitor, placed on top. Because of the internal layout and use of space, tower cases are usually easier to repair and upgrade.PHOTOS: Desktop Case, Desktop Case and Monitor, Desktop Case Open, Tower Case and Monitor, Tower Case Open
VIDEOS: Opening a tower case, Tower case removal, Desktop case removal
In addition to housing the components which make up a computer, the case also contains the system's power supply. There are two types of power supplies used in modern computers:
AT: the older of the two types, AT power supplies have two white connectors which attach to the computer's motherboard to provide power. The AT power supply also consists of a switch which mounts to the front of the case, as well as several large connectors which provide power to the drives and system components, and at least one smaller connector to provide power to floppy drives.
PHOTOS: AT power supply, AT power supply #2, AT power cables (Note: the black cables on thses connectors should always be placed next to one another), Floppy and hard drive power cables, AT switch, AT switch in case, AT switch in case 2, AT switch in case 3. The switch is screwed into the front panel of the case, so that the power button can be used to turn the computer on and off (Note: most cases come with the power supply already installed. You will likely never need to replace this switch - these photos are included only for the sake of completeness)
VIDEOS: AT power supply install (Note: most cases come with the power supply already installed), back panel power
ATX: most modern computers are built with this type of power supply, with one white connector which attaches to the computer's motherboard to provide power, a switch mounted to the front of the case, and the same connectors which provide power to the drives and system components found in AT power supplies. Additionally, ATX power supplies typically have a cable which connects to the motherboard, allowing the computer to shut itself off when the operating system is closed down.
PHOTOS: ATX power supply, ATX power cable, Floppy and hard drive power cables
VIDEOS: ATX power supply install, Shut Down (ATX computers shut off automatically during this process, AT systems need to be powered off manually with the switch on the front of the case).
