User Guide

Diagnostic Codes

Your system is equipped with four diagnostic code indicators, which are labeled "A," "B," "C," and "D" on the back of the computer. Each of the four indicators can be yellow, green, or off as shown in Table 1. When the computer is turned on or restarted and the system is functioning normally, the indicators flash during power-on self-test (POST). After the system starts, the indicators remain green to signify normal system operation.

If a malfunction is detected and the computer fails to start, the indicators display a code that identifies the problem. Write down the diagnostic code displayed and look it up in Table 1.

Table 1. Diagnostic Codes

Diagnostic Code	Definition	Corrective Action
	Power up default.	Make sure that the system is connected to a known working electrical outlet, and then check whether the front-panel power indicator is on or off. If the power indicator is off, check the power supply. If the problem persists, refer to Chapter 7, "Getting Help," of the Dell Dimension Lxxxc Systems Reference and Troubleshooting Guide for instructions on obtaining technical assistance. Remove all expansion cards. If the system still does not start, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	System board is receiving power, but the BIOS is not executing.	Set the configuration jumper to Maintenance mode and restart the system. Enter the system setup program and ensure that the microprocessor speed is set correctly. Exit and save the setting. Turn off the computer and reset the configuration jumper to Normal mode, and then restart the system. Remove all expansion cards and restart the system to determine if a resource conflict exists. If a conflict exists, resolve the conflict as described in "Resolving Software and Hardware Incompatibilities" in Chapter 5 of the Reference and Troubleshooting Guide. If the problem still persists, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	Recovery mode from BIOS failure.	Set the configuration jumper to Maintenance mode and restart the system. Enter the system setup program and ensure that the microprocessor speed is set correctly. Exit and save the setting. Turn off the computer and reset the configuration jumper to Normal mode, and then restart the system. If the problem persists, refer to Chapter 7, "Getting Help," if the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	Microprocessor has failed a BIOS test.	If the problem persists, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	Memory failed to be sized or enabled.	Reseat the DIMMs. If the problem persists, remove all but one DIMM, and then restart the system. Repeat this step until the malfunctioning DIMM is identified.
	PCI bus failure has occurred.	Remove all expansion cards and restart the system to determine if a resource conflict exists. If a conflict exists, resolve the conflict as described in "Resolving Software and Hardware Incompatibilities" in Chapter 5 of the Reference and Troubleshooting Guide. If the problem still persists, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	Video controller failed to initialize or respond.	If the problem persists, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	IDE bus failure has occurred.	Reseat the IDE cables. If the problem persists, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	USB port or a device connected to it has failed initialization.	Disconnect the device from the USB port. If the problem persists, refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	Other failure.	Refer to Chapter 7, "Getting Help," of the Reference and Troubleshooting Guide for instructions on obtaining technical assistance.
	System has started and turned over control to the operating system.	No action is necessary.

POST Beep Codes

If the monitor cannot display errors or problems, during power-on self-test (POST) the computer may emit a series of beeps, or beep code, that identifies the problem.

If the system emits a beep code and then fails to start, write down the beep code and look it up in Table 2.

Table 2. System Beep Codes

System Messages

The first column in Table 3 lists (in alphabetical order) system messages that may appear on the screen during the boot routine or during normal system operation. The second column in the table lists probable causes of the messages, and the third column either provides a corrective action or refers you to a source for resolving the problem.

Table 3. System Messages