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Advanced Troubleshooting

Dell™ Dimension™ 4590T Service Manual

  Diagnostic Lights

  Beep Codes

  System Messages

  Jumper Settings

Diagnostic Lights

To help you troubleshoot a problem, your computer has four lights labeled "A," "B," "C," and "D" on the back panel. The lights can be yellow or green. When the computer starts normally, the patterns or codes on the lights change as the boot process completes. If the POST portion of system boot completes successfully, all four lights display solid green. If the computer malfunctions during the POST process, the pattern displayed on the LEDs may help identify where in the process the computer halted.

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in your User's Guide.

Light pattern		Problem Description	Suggested Resolution
	off off off off	Normal off condition or possible pre-BIOS failure	Verify that the computer is plugged into a working outlet and that you have pressed the power button.
	green yellow yellow yellow	Possible BIOS failure; the computer is in the recovery mode	Run the BIOS Recovery Utility, wait for recovery completion, and restart the computer to retest.
	yellow green yellow yellow	Possible processor failure	Reseat the processor, and restart the computer to retest.
	green green yellow yellow	Possible memory failure	Reseat all memory modules and restart the computer to retest.
	yellow yellow green yellow	Possible expansion card failure	Remove each expansion card individually, and restart the computer to retest. Reinstall the expansion card(s) one at a time, and restart the computer to retest. Move each expansion card one at a time to another PCI slot, and restart the computer to retest.
	green yellow green yellow	Possible video card failure or bad on-board video	If you have a video card, reseat it and restart the computer to retest. If you have integrated video, you must replace the system board.
	yellow green green yellow	Possible floppy or hard drive failure	Reseat all power and data cables, and restart the computer to retest.
	green green green yellow	Possible USB failure	Reseat all USB devices and cables, and restart the computer to retest.
	yellow yellow yellow green	No memory detected	Reseat all memory modules and restart the computer. If the problem still exists, to eliminate the possibility of a faulty memory connector, install one memory module (if the computer supports a single module), and restart the computer. Then move the module to another connector and restart the computer.
	yellow green yellow green	Memory is detected, but a memory configuration or compatibility error exists	Be sure that the memory modules are compatible with your computer. If necessary, replace the memory modules.
	yellow green green green	Other failure	Check the computer message that appears on your monitor screen.
	green green green green	Normal operating condition after POST	None.

Beep Codes

Your computer might emit a series of beeps that identify a problem. One possible series (code 1-3-1) consists of one beep, a burst of three beeps, and then one beep. This series tell you that the computer encountered a memory problem.

Try to resolve the problem — Write the beep code down on the Diagnostics Checklist (see "Before You Call" in the "Getting Help" section of your User's Guide), and perform the action recommended in the following table.

Run the Dell Diagnostics to identify a more serious cause

See "Contacting Dell" in your User's Guide for technical assistance

Code	Cause	Action
1-1-2	Microprocessor register failure	See "Contacting Dell" in your User's Guide for technical assistance.
1-1-3	NVRAM	Run the Dell Diagnostics, if possible.
1-1-4	ROM BIOS checksum failure	Run the Dell Diagnostics, if possible.
1-2-1	Programmable interval timer	Run the Dell Diagnostics, if possible.
1-2-2	DMA initialization failure	Run the Dell Diagnostics, if possible.
1-2-3	DMA page register read/write failure	Run the Dell Diagnostics, if possible.
1-3	Video Memory Test failure	Run the Dell Diagnostics, if possible.
1-3-1 through 2-4-4	DIMMs not being properly identified or used	See "Memory Problems" in your User's Guide.
3-1-1	Slave DMA register failure	Run the Dell Diagnostics, if possible.
3-1-2	Master DMA register failure	Run the Dell Diagnostics, if possible.
3-1-3	Master interrupt mask register failure	See "Contacting Dell" in your User's Guide for technical assistance.
3-1-4	Slave interrupt mask register failure	See "Contacting Dell" in your User's Guide for technical assistance.
3-2-2	Interrupt vector loading failure	See "Contacting Dell" in your User's Guide for technical assistance.
3-2-4	Keyboard Controller Test failure	Run the Dell Diagnostics, if possible.
3-3-1	NVRAM power loss	Run the Dell Diagnostics, if possible.
3-3-2	NVRAM configuration	Run the Dell Diagnostics, if possible.
3-3-4	Video Memory Test failure	Run the Dell Diagnostics, if possible.
3-4-1	Screen initialization failure	Run the Dell Diagnostics, if possible.
3-4-2	Screen retrace failure	Run the Dell Diagnostics, if possible.
3-4-3	Search for video ROM failure	Run the Dell Diagnostics, if possible.
4-2-1	No time tick	See "Contacting Dell" in your User's Guide for technical assistance.
4-2-2	Shutdown failure	See "Contacting Dell" in your User's Guide for technical assistance.
4-2-3	Gate A20 failure	See "Contacting Dell" in your User's Guide for technical assistance.
4-2-4	Unexpected interrupt in protected mode	See "Contacting Dell" in your User's Guide for technical assistance.
4-3-1	Memory failure above address 0FFFFh	Run the Dell Diagnostics, if possible.
4-3-3	Timer-chip counter 2 failure	See "Contacting Dell" in your User's Guide for technical assistance.
4-3-4	Time-of-day clock stopped	See "Contacting Dell" in your User's Guide for technical assistance.
4-4-1	Serial or parallel port test failure	Run the Dell Diagnostics, if possible.
4-4-2	Failure to decompress code to shadowed memory	Run the Dell Diagnostics, if possible.
4-4-3	Math-coprocessor test failure	Run the Dell Diagnostics, if possible.
4-4-4	Cache test failure	Run the Dell Diagnostics, if possible.

System Messages

NOTE: If the message you received is not listed in the table, see the documentation for either the operating system or the program that was running when the message appeared.

Message	Possible Cause	Corrective Action
8042 Gate-A20 error	The keyboard controller failed its test.	If you receive this message after you make changes in system setup, enter the program and restore the original value(s).
Address Line Short!	An error in the address decoding circuitry in the memory has occurred.	Reseat the memory modules.
C: Drive Error C: Drive Failure	The hard drive is not working or is not configured correctly.	Ensure that the drive is installed correctly in the computer and defined correctly in system setup.
Cache Memory Bad, Do Not Enable Cache	The cache memory is not operating.	See "Contacting Dell" in your User's Guide for instructions on obtaining technical assistance.
CH-2 Timer Error	An error is occurring on the timer on the system board.	See "Contacting Dell" in your User's Guide for instructions on obtaining technical assistance.
CMOS Battery State Low CMOS Checksum Failure CMOS System Options Not Set CMOS Display Type Mismatch CMOS Memory Size Mismatch CMOS Time and Date Not Set	The system configuration information in the system setup program is incorrect or the battery charge may be low.	Enter system setup, verify the system configuration, and then restart the computer.
Diskette Boot Failure	Drive A or B is present but has failed the BIOS POST.	Ensure that the drive is installed correctly in the computer and defined correctly in system setup. Check the interface cable at both ends.
DMA Error DMA 1 Error DMA 2 Error	Error in the DMA controller on the system board.	The keyboard or system board may need to be replaced.
FDD Controller Failure HDD Controller Failure	The BIOS cannot communicate with the floppy drive or hard drive controller.	Ensure that the floppy drive or the hard drive is installed correctly in the computer and defined correctly in system setup. Check the interface cable at both ends.
INTR1 Error INTR2 Error	An interrupt channel on the system board failed to POST.	The keyboard or system board may need to be replaced.
Invalid Boot Diskette	The operating system cannot be located on drive A or drive C.	Enter system setup and confirm that drive A or drive C is properly identified.
Keyboard Error	The BIOS has detected a stuck key.	Ensure that nothing is resting on the keyboard; if a key appears to be stuck, carefully pry it up. If the problem persists, you may need to replace the keyboard.
KB/Interface Error	An error occurred with the keyboard connector.	Ensure that nothing is resting on the keyboard; if a key appears to be stuck, carefully pry it up. If the problem persists, you may need to replace the keyboard.
No ROM Basic	The operating system cannot be located on drive A or drive C.	Enter system setup and confirm that drive A or drive C is properly identified.

Jumper Settings

NOTICE: Ensure that your computer is turned off and unplugged before you change the jumper settings. Otherwise, damage to your computer or unpredictable results can occur.

CAUTION: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your computer's electronic components. You can do so by touching an unpainted metal surface on the computer chassis.

To change a jumper setting, pull the plug off its pin(s) and carefully fit it down onto the pin(s) indicated.

Jumper	Setting	Description
PSWD	(default)	Password features are enabled. Password features are disabled.
RTCRST		Real-time clock reset.
jumpered   unjumpered

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