5-4 Dell OptiPlex GXa Mini Tower Systems Reference and Installation Guide
Jumpers
A jumper is referred to as open or unjumpered when the
plug is pushed down over only one pin or if there is no
plug at all. When the plug is pushed down over two pins,
the jumper is referred to as jumpered. In some docu-
ments, the jumper setting may be shown in text as two
numbers, such as 1-2. The number 1 is printed on the cir-
cuit board so that you can identify each pin number based
on the location of pin 1.
Figure 5-6 shows the location and default settings of the
jumper blocks on your system board. See Table 5-1 for
the designations, default settings, and functions of your
system’s jumpers.
Switches
Switches control various circuits or functions in your
computer system. The switches you are most likely to
encounter are dual in-line package (DIP) switches, which
are normally packaged in groups of two or more switches
in a plastic case. Two common types of DIP switches are
slide switches and rocker switches (see the following
illustration).
Each of these switches has two positions, or settings
(usually on and off). To change the setting of a slide
switch, use a small, pointed object such as a small screw-
driver or a straightened paper clip to slide the switch to
the proper position. To change the setting of a rocker
switch, use the screwdriver or paper clip to press down
on the appropriate side of the switch. In either case, do
not use a pen, pencil, or other object that might leave a
residue on the switch.
CAUTION: Make sure your system is turned off
before you change a jumper setting. Otherwise,
damage to your system or unpredictable results
may occur.
Jumpers are small blocks on a circuit
board with two or more pins
emerging from them.
Plastic plugs containing a wire fit
down over the pins. The wire connects
the pins and creates a circuit.
To change a jumper setting, pull the plug
off its pin(s) and carefully fit it down onto
the pin(s) indicated.
slide switches rocker switches