Diagnostic LEDs List for Dell OptiPlex, Dimension, Precision Workstations

GYYY: Memory not detected.
YYGG: Memory Subsystem configuration activity or failure.
YGGY: Storage device configuration or failure.
YYYY: The system board is receiving power, but the BIOS is not executing.
YGGG: USB Subsystem configuration activity or failure.
YGYY: PCI device configuration or failure.
GYGG: Routine System Activity preceding video initialization.
GGGY: POST is complete, but unable to hand off control to the OS.
GGGG - System has released control to OS.
GYYG: Fatal Motherboard Failure.
YGYG: Video Subsystem configuration or failure.
YYGY: CPU configuration activity or failure.
YYYG: BIOS Checksum failure or System is in Recovery Mode.
GGYY: System resource configuration.
GYGY: Memory Configuration / Compatibility Error.
GGYG: System Resource Conflict.


Recent version

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.
G: 4	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.
G: 3	A possible processor failure has occurred.	Reinstall the processor and restart the computer.
G: 3,4	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).
G: 2,4	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).
G: 2,3	A possible floppy or hard drive failure has occurred.	Reseat all power and data cables and restart the computer.
G: 2,3,4	A possible USB failure has occurred.	Reinstall all USB devices, check cable connections, and then restart the computer.
G: 1	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).
G: 1, 3	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).
G: 1,2,3	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).
G: 1,2,3,4	After POST is complete, all four diagnostic lights turn green briefly before turning off to indicate normal operating condition.	None.