This section provides specific information about the system jumpers. It also provides some basic information on jumpers and switches 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 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 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. Figure 5-1 shows an example of a jumper.
Figure 5-1. Example Jumpers
CAUTION: 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 5-2 shows the location and default settings of the jumper blocks on the system board. See Table 5-1 for the designations, default settings, and functions of the system's jumpers.
Figure 5-2 shows the location of the configuration jumpers and connector on the I/O riser card. Table 5-1 and Table 5-2 list the jumpers and connectors.
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, change the jumper setting to 1–2 and boot the system. Change the jumper setting back to 2–3 before restoring the configuration information.)
(default)
(default)
