System Lights & Diagnostic Lights Dell OptiPlex 360

System Lights

Your power button light and hard-drive light may indicate a computer problem.

Power Light	Problem Description	Suggested Resolution
Solid green	Power is on, and the computer is operating normally. On the desktop computer, a solid green light indicates a network connection.	No corrective action is required.
Blinking green	The computer is in a power-saving mode (Microsoft® Windows® XP).	Press the power button, move the mouse, or press a key on the keyboard to wake the computer.
Blinks green several times and then turns off	A configuration error exists.	Check the diagnostic lights to see if the specific problem is identified (see Diagnostic Lights).
Solid yellow	The Dell Diagnostics is running a test, or a device on the system board may be faulty or incorrectly installed.	If the Dell Diagnostics is running, allow the testing to complete. If the computer does not boot, contact Dell for technical assistance (see Contacting Dell).
Blinking yellow	A power supply or system board failure has occurred.	See Power Problems.
Solid green and a beep code during POST	A problem was detected while the BIOS was executing.	See Beep Codes for instructions on diagnosing the beep code. Also, check the diagnostic lights to see if the specific problem is identified (see Diagnostic Lights).
Solid green power light and no beep code and no video during POST	The monitor or the graphics card may be faulty or incorrectly installed.	Check the diagnostic lights to see if the specific problem is identified (see Diagnostic Lights). See Video and Monitor Problems.
Solid green power light and no beep code but the computer locks up during POST	An integrated system board device may be faulty.	Check the diagnostic lights to see if the specific problem is identified (see Diagnostic Lights). If the problem is not identified, contact Dell for technical assistance (see Contacting Dell).

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Diagnostic Lights

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions located in the Product Information Guide.

To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" on the front or back panel. The lights can be off 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.

NOTE: The orientation of the diagnostic lights may vary dependent upon the computer type. The diagnostic lights can appear either vertical or horizontal.

Light Pattern	Problem Description	Suggested Resolution
	The computer is in a normal "off" condition, or a possible pre-BIOS failure has occurred. The diagnostic lights are not lit after the computer successfully boots to the operating system.	Plug the computer into a working electrical outlet and press the power button.
	A possible BIOS failure has occurred; the computer is in the recovery mode.	Run the BIOS Recovery utility, wait for recovery completion, and then restart the computer.
	A possible processor failure has occurred.	Reinstall the processor and restart the computer.
	Memory modules are detected, but a memory failure has occurred.	If you have one memory module installed, reinstall it and restart the computer. (see Memory for instructions on how to remove and install memory modules.) If you have two or more memory modules installed, remove the modules, reinstall one module, and then restart the computer. If the computer starts normally, reinstall an additional module. Continue until you have identified a faulty module or reinstalled all modules without error. If available, install properly working memory of the same type into your computer. If the problem persists, contact Dell (see Contacting Dell).
	A possible graphics card failure has occurred.	If the computer has a graphics card, remove the card, reinstall it, and then restart the computer. If the problem still exists, install a graphics card that you know works and restart the computer. If the problem persists or the computer has integrated graphics, contact Dell (see Contacting Dell).
	A possible floppy or hard drive failure has occurred.	Reseat all power and data cables and restart the computer.
	A possible USB failure has occurred.	Reinstall all USB devices, check cable connections, and then restart the computer.
	No memory modules are detected.	If you have one memory module installed, reinstall it and restart the computer. (see Memory for instructions on how to remove and install memory modules.) If you have two or more memory modules installed, remove the modules, reinstall one module, and then restart the computer. If the computer starts normally, reinstall an additional module. Continue until you have identified a faulty module or reinstalled all modules without error. If available, install properly working memory of the same type into your computer. If the problem persists, contact Dell (see Contacting Dell).
	Memory modules are detected, but a memory configuration or compatibility error exists.	Ensure that no special memory module/memory connector placement requirements exist (see Memory). Verify that the memory modules that you are installing are compatible with your computer (see Memory). If the problem persists, contact Dell (see Contacting Dell).
	A failure has occurred. This pattern also displays when you enter system setup (see Entering System Setup) and may not indicate a problem.	Ensure that the cables are properly connected to the system board from the hard drive, CD drive, and DVD drive. Check the computer message that appears on your monitor screen. If the problem persists, contact Dell (see Contacting Dell).
	After POST is complete, all four diagnostic lights turn green briefly before turning off to indicate normal operating condition.	None.

Beep Codes

Your computer might emit a series of beeps during start-up if the monitor cannot display errors or problems. This series of beeps, called a beep code, identifies a problem. One possible beep code (code 1-3-1) consists of one beep, a burst of three beeps, and then one beep. This beep code tells you that the computer encountered a memory problem.

If your computer beeps during start-up:

1. Write down the beep code on the Diagnostics Checklist.
   
   
2. Run the Dell Diagnostics to identify a more serious cause (see Dell Diagnostics).
   
   
3. Contact Dell for technical assistance (see Contacting Dell).

Code	Cause
1-1-2	Microprocessor register failure
1-1-3	NVRAM read/write failure
1-1-4	ROM BIOS checksum failure
1-2-1	Programmable interval timer failure
1-2-2	DMA initialization failure
1-2-3	DMA page register read/write failure
1-3	Video Memory test failure
1-3-1 through 2-4-4	Memory not being properly identified or used
3-1-1	Slave DMA register failure
3-1-2	Master DMA register failure
3-1-3	Master interrupt mask register failure
3-1-4	Slave interrupt mask register failure
3-2-2	Interrupt vector loading failure
3-2-4	Keyboard Controller test failure
3-3-1	NVRAM power loss
3-3-2	Invalid NVRAM configuration
3-3-4	Video Memory test failure
3-4-1	Screen initialization failure
3-4-2	Screen retrace failure
3-4-3	Search for video ROM failure
4-2-1	No timer tick
4-2-2	Shutdown failure
4-2-3	Gate A20 failure
4-2-4	Unexpected interrupt in protected mode
4-3-1	Memory failure above address 0FFFFh
4-3-3	Timer-chip counter 2 failure
4-3-4	Time-of-day clock stopped
4-4-1	Serial or parallel port test failure
4-4-2	Failure to decompress code to shadowed memory
4-4-3	Math-coprocessor test failure
4-4-4	Cache test failure