Dell 6100, Инструкция по установке и устранению неисправностей

Страница: 135 / 157

Jumpers, Switches, and Connectors C-1
Appendix C
Jumpers, Switches, and Connectors
T
his appendix provides specific information about the
jumpers on the system board. It also provides some basic
information on jumpers and switches and describes the
connectors and sockets on the various boards in the
computer.
J
umpers and Switches—
A General Explanation
Jumpers and switches provide a convenient and revers-
ible way of reconfiguring the circuitry on a printed circuit
board. When reconfiguring the system, you may need to
change jumper settings on the system board. You may
also need to change jumper and/or switch settings on
expansion cards or drives.
Jumpers
To change a jumper setting, pull the plug off its pin(s)
and carefully fit it down onto the pin(s) indicated.
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. The jumper setting
is often shown in text as two numbers, such as 1-2. The
number 1 is printed on the circuit board so that you can
identify each pin number based on the location of pin 1.
Figure C-1 shows the location and default settings of the
jumper blocks on the system board. See Table C-1 for the
designations, default settings, and functions of the sys-
tem’s jumpers.
Switches
Switches control various circuits or functions in the
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
CAUTION: Make sure the system is turned off
before you change a jumper setting. Otherwise,
damage to the 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.
slide switches rocker switches