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Jumpers and Connectors

Dell™ PowerEdge™ 2500 Systems Installation and Troubleshooting Guide

  Jumpers—A General Explanation

  System Board Jumpers

  System Board Connectors

  SCSI Backplane Board Connectors

  Interposer Board Connectors

  Disabling a Forgotten Password

This section 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.

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 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. Figure A-1 shows an example of a jumper.

Figure A-1. Example Jumpers

WARNING: 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 A-2 shows the location and default settings of the jumper blocks on the system board. See Table A-1 for the designations, default settings, and functions of the system's jumpers.

System Board Jumpers

Figure A-2 shows the location of the configuration jumpers on the system board. Table A-1 lists the function of these jumpers.

Figure A-2. System Board Jumpers

Table A-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.)

ONCE

 

Reserved (do not change).

jumpered unjumpered

NOTE: For the full name of an abbreviation or acronym used in this table, see "Abbreviations and Acronyms."

System Board Connectors

See Figure 6-1 and Table 6-1for the location and description of system board connectors.

SCSI Backplane Board Connectors

Figure A-3 shows the location of the connectors on the back of the SCSI backplane board.

Figure A-3. Connectors on the SCSI Backplane Board

Interposer Board Connectors

Figure A-4 shows the connectors and sockets located on the interposer board.

Figure A-4. Connectors on the Interposer Board

Disabling a Forgotten Password

The computer's software security features include a system password and a setup password, which are discussed in detail in Section 4, "Using the System Setup Program," in 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 system password or setup password, perform the following steps.

CAUTION: See "Protecting Against Electrostatic Discharge" in the safety instructions at the front of this guide.
  1. Open the front bezel (see "Removing the Front Bezel" in "Troubleshooting Your System").

  2. Remove the system cover.

  3. Refer to Figure A-2 for the location of the password jumper (labeled "PASSWD") on the system board.

  4. Remove the jumper plug from the PASSWD jumper.

  5. Replace the right-side computer 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 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.
  1. Repeat step 1.

  2. Install the jumper plug on the PASSWD jumper.

  3. Replace the right-side computer cover, and then reconnect the computer and peripherals to their electrical outlets and turn them on.

  4. Assign a new system and/or setup password.

To assign a new system password using the System Setup program, see "Assigning a System Password" in the User's Guide.

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