Dell OptiPlex GXa Reference And Installation Manual page 57

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).
slide switches rocker switches
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
Working Inside Your Computer 5-5