(^346) PC Hardware: A Beginner’s Guide
Some screwless cases have an indentation at the bottom of the front panel so you can
grasp the edge to pull it up. On others, where no such handhold is provided, you may
need to use a small screwdriver or pry bar to pull the front panel up enough to gain a
gras pof its edge. A minor drawback to a screwless case is that you will have several case
parts to keep track of instead of just the one-piece legacy type case.
Release-Button Desktops
This type of case, which is used by Compaq for its desktop models, is removed by press-
ing release buttons located on the front (on Compaq desktops) or rear of the PC. After
pressingthereleasebuttons,thecover,whichincludesthefront,rear,top,andsidesofthe
cover, lift straight off the case.
Another case in this grou pis the fli p-to pcase. This case also uses release buttons to
unlock the cover, but instead of the entire to plifting off, the to pcover lifts u plike a
top-loading washer or CD player. If for some reason you need to remove the entire case,
strategically placed screws can be removed to do this.
Front-Screw Cases
On this case style, the screws that hold the cover on the PC are located on the front panel,
usually hidden behind sliding tabs or a snap-on panel. Removing these front-panel screws
(and possibly some on the rear panel as well) allows the case to be pulled forward and off
the case.
The form factors (AT, ATX, LPX, etc.) mentioned in this section and the various case
styles(desktop,tower,andothers)arelookedatinalittlemoredetaillaterinthechapter.
The Front Panel
The primary purpose of thefront panel,orbezel, as it is also called, is to cover u pthe front
end of the chassis, but since it is the part that the user looks at most of the time, efforts
have been made to make it useful and appealing (see Figure 15-5).
Some PCs now also feature doors and snap-on panels to mask disk drives, the power
and reset switches, and even the LEDs on the front of the PC. Typically, doors on the front
panel are a characteristic of larger PCs and network servers. Figure 15-6 shows a server
with two doors, one for the removable drives and the other to cover the normal parts of
the front panel. This computer also features a key lock for the doors to provide a small
amount of security.Status LEDs
Most PCs have LEDs (light emitting diodes) on the front panel to show the status and ac-
tivity of certain parts of the system. Typically, there are two LEDs: one that is lighted
when the power is on and one that indicates when the hard disk is being accessed. There
are other LEDs visible on the front of the PC, but they are generally a part of a disk drive
installedinadrivebay.VeryoldPCsalsohaveaTurboLEDthatindicatesthesystemisin
turbo mode, which raises the processor speed of the PC. These systems are generally
obsolete now.