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Jumpers and Connectors: Dell™ PowerEdge™ 2500 and 2500SC Systems Service Manual

	Overview		System Board Labels
	Jumpers—A General Explanation		SCSI Backplane Boards
	System Board Jumpers		Disabling a Forgotten Password

Overview

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 — A General Explanation

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.

System Board Jumpers

Figure 1 shows the location of the configuration jumpers on the system board. Table 1 lists the function of these jumpers.

Figure 1. System Board Jumpers

Table 1. System-Board Jumper Settings

Jumper	Setting		Description
PASSWD		(default)	The password feature is enabled. The password feature is disabled.
NVRAM CLR		(default)	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.
RSVD		(default)	Reserved (do not change).
jumpered      unjumpered

System Board Labels

Table 2 lists the connectors and sockets located on the system board.

Table 2. System Board Connectors and Sockets

SCSI Backplane Boards

Figure 2 shows the location of the connectors on the front of the SCSI backplane board.

Figure 2. SCSI Backplane Board Connectors

1 Daughter card connector 2 SCSI slot 0 3 SCSI slot 1 4 SCSI slot 2 5 Front fan power 6 SCSI slot 3 7 SCSI slot 4 8 SCSI slot 5

Disabling a Forgotten Password

The computer's software security features include a supervisor password and a user password, which are discussed in detail in "Using the System Setup Program" of the User's Guide. 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 supervisor password or user password, perform the following steps.

CAUTION: Read the safety instructions in your System Information document.

1. Turn off the system, including any attached peripherals, and disconnect the power cord from its power source.
   
   
2. Open the front bezel.
   
   
3. Remove the system cover.
   
   
4. Refer to "System Board Jumpers" for  the location of the password jumper (labeled PASSWD) on the system board.
   
   
5. Remove the jumper plug from the PASSWD jumper.
   
   
6. Replace the system cover and then 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 user password, you must install the jumper plug.

NOTE: If you assign a new system and/or user password with the jumper plug still removed, the system disables the new password(s) the next time it boots.

7. Repeat step 1.
   
   
8. Install the jumper plug on the PASSWD jumper.
   
   
9. Replace the system cover and then reconnect the computer and peripherals to their electrical outlets and turn them on.
   
   
10. Close the front bezel.
    
    
11. Assign a new system and/or user password.
    
    To assign a new system and/or user password, see Using the System Setup Program.

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