Case Components
As shown in Figure 15-2, not all system cases are identical in size or shape, but most con-
tain components and parts common to all PC cases. Here is a list of the most common sys-
tem components found in PC cases: Chassis The skeletal framework that provides the structure, rigidity, and
strength of the case.
Cover Plays an important role in the cooling, protection, and structure of the PC.
Power supply A very important component, not only to the case assembly,
but to the PC and its other components. The primary tasks of the power supply
are to rectify (convert) AC power into DC power for use by the PC’s internal
components and to house and power the mail system cooling fan. Power supplies
are not discussed in detail in this chapter, other than to discuss their conformity
to the various form factors and their fit into the different case styles. See
Chapter 14 for more information on power supplies.
Front panel In addition to providing the PC with its looks and color, the
front panel also provides information on the PC’s status, allows the user to
physically secure the PC, and, on some case types, is the starting point for
removing the case cover.
Switches Most newer systems now have their two main switches, the power
switch and the reset switch, on the front panel. If the power switch is not on
the front panel, it is likely either on the right rear corner or near a corner on
the back of the PC.
Drive bays Beginning with the PC XT, disk drives with removable media
have been mounted in the system case so that they can be accessed from the
front panel. Typically, the drive bays are used for 5.25-inch and 3.5-inch disk
drives, such as floppy disks, CD-ROMs, DVDs, and removable hard drives.The Chassis
Beneath the sheet metal or plastic exterior of the case is a metal framework that provides
the structural framework for the PC. Just like the interior of a building or the human skel-
eton—to stretch the point—the PC’s chassis (pronounced “chass-ee”) provides the frame
on which all other parts of the PC mount, attach, or hang. As shown in Figure 15-3, the
sheet metal of the chassis gives the PC its shape, size, rigidity, strength, and the location
of its components.Construction
The frame of the PC must be a rigid structure. Many of the components and devices in the
PC cannot withstand being flexed, especially when the devices are operating. The one
component of the PC that strength of the frame protects most is the motherboard. If the(^342) PC Hardware: A Beginner’s Guide