This section provides specific information about the jumpers on the system board. It
also provides some basic information on jumpers and describes the connectors
and sockets on the various boards in the system.
Jumpers provide a convenient and reversible way of
reconfiguring the circuitry on a printed circuit board. When installing replacement parts
or reconfiguring the system, you may need to change jumper settings on the system board.
You may also need to change jumper settings on expansion cards or drives.
Jumpers
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.
NOTICE: Make sure the system is turned off before you change
a jumper setting. Otherwise, damage to the system or unpredictable results may occur.
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 1 shows the location of the configuration jumpers
and the SW_NMI switch on the
system board. Table 1 lists the function of these
configuration jumpers.
The configuration settings are retained at system boot.
The configuration settings are cleared at next system boot. If the configuration settings
become corrupted to the point where the system will not boot, install the jumper plug and
boot the system. Remove the jumper before restoring the configuration information.
The computer's software security features include a system
password and a setup password, which are discussed in detail in "Using the System
Setup Program." A password jumper on the system board
enables these password features or disables them and clears any password(s) currently in
use.
To disable a forgotten system password or setup password, perform
the following steps.
CAUTION: Read the safety instructions
in your System Information document.
Turn off the system, including any attached peripherals, and disconnect the
power cord from its power source.
Reconnect
the computer to an electrical outlet and turn it on.
The existing passwords are not disabled (erased) until the system boots with the PASSWD
jumper plug removed. However, before you assign a new system and/or setup password, you
must install the jumper plug.
NOTE: If you assign a new system
and/or setup password with the jumper plug still removed, the system disables the new
password(s) the next time it boots.
jumpered
unjumpered
