Dell PowerVault 775N (Rackmount NAS Appliance) - Manual (Page 79)

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Jumpers and Connectors
Dell™ PowerVault™ 775N Systems Service Manual
Jumpers—A General Explanation
System Board Jumpers
System Board Connectors
Expansion-Card Riser-Board Components and PCI Buses
SCSI Backplane Board Connectors
This section provides specific information about the system jumpers. It also provides some basic information on jumpers and
switches and describes the connectors on the various boards in the system.
Jumpers—A General Explanation
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 circuit boards 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. Figure 5-1 shows an example of a jumper.
Figure 5-1. Example Jumpers
CAUTION: Ensure that 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.
System Board Jumpers
Figure 5-2 shows the location and default settings of the system jumper blocks. See Table 5-1 for the designations, default
settings, and functions of the system's jumpers.
Figure 5-2. System Board Jumpers