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A Reference Guide to the Precision Workstation Diagnostic Indicators

Summary: This article is a reference guide to the various methods used on Dell Precision workstations to diagnose No POST faults during startup.

This article may have been automatically translated. If you have any feedback regarding its quality, please let us know using the form at the bottom of this page.

Article Content


Instructions

Dell Precision Workstation systems have a long history of built-in diagnostic indicators. These can be audible beeps, power buttons that display different states and colors, specific diagnostics LEDs or a combination of them all, in order to indicate at which point during the Power On Self-Test (POST) a system is having issues.

The following article is a reference guide to the codes available on each model and what those codes mean. These change through the various models and years. These indicators are merely a starting point for narrowing down any troubleshooting to be carried out to identify the cause of your current issue. You can use this as a starting point to narrow down the proper troubleshooting guide required, or you can contact technical support for further help and they will be looking for these indicators as well.


Table of Contents:

  1. Diagnostic LED Codes for the Precision series (2017 to Present)
  2. Diagnostic LED Codes for the Precision series (2014 to 2017)
  3. Diagnostic LED Codes for the Precision series (2012 to 2013)
  4. Diagnostic LED Codes for the Precision Series (2010 to 2011)
  5. Diagnostic LEDs and Beep Codes for the Precision series (Prior to 2009)
  6. Glossary of Acronyms
  7. Diagnostic Indicator Guides
Note: For all the tables below, remember that the diagnostic LEDs only serve as an indicator of the progress through the POST process. These LEDs do not indicate the problem that caused the POST routine to stop.

Diagnostic LEDs and Beep Codes for the Precision series (2017 to Present)

With the latest series, the Power Button state now gives a new blink and color shift pattern that uses both Amber and White power LED flashes to indicate where it had a problem. You can identify these systems by the fact that there is no Diagnostics LED block on the front of the unit.

2017 to present Precision Workstations

Power Button LED State Description
Power LED off Off Power is Off. LED is blank.
Power LED blinking amber Blinking Amber Initial State of LED at power on. See the table below for Blinking Amber pattern diagnostic suggestions and possible failures.
Power LED solid amber Solid Amber The second state of the LED at power on, indicates that the POWER_GOOD signal is active and it is probable that the power supply is fine.
Power LED blinking white Blinking White System is in a low-power state, either S1 or S3. This does not indicate a fault condition.
Power LED solid white Solid White System is in S0 state. This is the normal power states of a functioning machine. The BIOS turns the LED to this state to indicate it has started fetching op-codes.
State State Name Power Light:
Amber Blinking
Amber Blinking Pattern Problem Description Suggested Resolution
- - 1, 1 1 amber blink followed by a short pause, 1 white blink, long pause, then repeats Bad Motherboard
  • Contact Tech Support to troubleshoot the motherboard
- - 1, 2 1 amber blink followed by a short pause, 2 white blinks, long pause, then repeats Bad Motherboard, Power Supply, or Power Supply cabling
  • If you can assist to troubleshoot, narrow down the issue with PSU BIST Test, reseat cable.
  • If nothing works, contact Tech Support
- - 1, 3 1 amber blink followed by a short pause, 3 white blinks, long pause, then repeats Bad Motherboard, Memory, or Processor
  • If you can assist to troubleshoot, narrow down the issue by reseating memory and swapping a known good memory if available.
  • If nothing works, contact Tech Support
- - 1, 4 1 amber blink followed by a short pause, 4 white blinks, long pause, then repeats Bad Coin Cell Battery
  • CPU configuration activity is in progress, or a CPU Failure was detected
  • Contact Tech Support
S2 CPU 2, 1 2 amber blinks followed by a short pause, 1 white blinks, long pause, then repeats Bad Processor
  • CPU configuration activity is in progress, or a CPU failure was detected.
  • Contact Tech Support
S1 RCM 2, 2 2 amber blinks followed by a short pause, 2 white blinks, long pause, then repeats BIOS ROM Failure
  • System is in Recovery Mode.
  • Flash latest BIOS version. If problem persists, contact Tech Support
S6 STO 2, 3 2 amber blinks followed by a short pause, 3 white blinks, long pause, then repeats No Memory detected
  • If customer can assist to troubleshoot, narrow down the issue by removing one by one memory to determine which one failed and swapping to a known good memory if available to confirm.
  • Contact Tech Support.
S3 MEM 2, 4 2 amber blinks followed by a short pause, 4 white blinks, long pause, then repeats Memory failures
  • Memory subsystem configuration activity is in progress. Appropriate memory modules were detected, but a memory failure has occurred.
  • If you can assist to troubleshoot, narrow down the issue with reseating memory and swapping a known good memory if available.
  • If nothing works, contact Tech Support.
S8 MEM 2, 5 2 amber blinks followed by a short pause, 5 white blink, long pause, then repeats Invalid memory installed
  • Memory subsystem configuration activity is in progress. Appropriate memory modules were detected but appear to be incompatible or in an invalid configuration.
  • If you can assist to troubleshoot, narrow down the issue with reseating memory and swapping a known good memory if available.
  • If nothing works, contact Tech Support.
S9 MBF 2, 6 2 amber blinks followed by a short pause, 6 white blinks, long pause, then repeats Motherboard: Chipset
  • System board failure detected.
  • If customer can assist to troubleshoot, narrow down the issue by removing components one by one to determine which component failed.
  • Contact Tech Support.
- - 3, 1 3 amber blinks followed by a short pause, 1 white blink, long pause, then repeats RTC Power Failure
  • If customer can assist to troubleshoot, narrow down the issue by swapping for known good (working) CMOS Battery.
  • Contact Tech Support.
S4 PCI 3, 2 3 amber blinks followed by a short pause, 2 white blinks, long pause, then repeats PCI Device or Video
  • PCI device configuration activity is in progress, or PCI device failure was detected.
  • If you can assist to troubleshoot, narrow down the issue by reseating PCI card and removing one by one to determine which card failed.
  • Contact Tech Support.
- - 3, 3 3 amber blinks followed by a short pause, 3 white blinks, long pause, then repeats BIOS Recovery 1
  • System is in recovery mode
  • Flash with latest BIOS revision and Contact Tech Support if still not resolved
- - 3, 4 3 amber blinks followed by a short pause, 4 white blinks, long pause, then repeats BIOS Recovery 2
  • System is in recovery mode
  • Flash with latest BIOS revision and Contact Tech Support if still not resolved
- - 4, 1 4 amber blinks followed by a short pause, 1 white blink, long pause, then repeats CPU Configuration or CPU Failure
  • If you can assist to troubleshoot, narrow down the issue by removing parts until minimum required to POST.
  • Contact Tech Support.
- - 4, 2 4 amber blinks followed by a short pause, 2 white blinks, long pause, then repeats Generic Post Video Error
  • If you can assist to troubleshoot, narrow down the issue by switching between onboard and a discrete video card to determine where fault falls.
  • Contact Tech Support.
- - 4, 3 4 amber blinks followed by a short pause, 3 white blinks, long pause, then repeats Bad Memory
  • If you can assist to troubleshoot, narrow down the issue by trying memory DIMMs individually in each slot and test with known good (working) memory to determine where the fault lies.
  • Contact Tech Support.
- - 4, 4 4 amber blinks followed by a short pause, 4 white blinks, long pause, then repeats Riser Board Issue
  • If you can assist to troubleshoot, narrow down the issue by removing parts until minimum required to POST to determine point of failure.
  • Contact Tech Support.
- - 4, 5 4 amber blinks followed by a short pause, 5 white blinks, long pause, then repeats PCIe Add-in Card Population Issue
  • If you can assist to troubleshoot, narrow down the issue by primary video card only.
  • Contact Tech Support.
- - 4, 6 4 amber blinks followed by a short pause, 6 white blinks, long pause, then repeats RAID Volume degraded
  • RAID volume is degraded.
  • If possible, boot to the F12 menu to enter the device configuration tab and rebuild the RAID volume.
  • Contact Tech Support if issue persists.
- - 4, 7 4 amber blinks followed by a short pause, 7 white blinks, long pause, then repeats System Side cover is missing
  • System side cover (either left or right) is missing.
  • Install the side covers and restart.
  • Contact Tech Support if not resolved.

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Diagnostic LEDs and Beep Codes for the Precision series (2014 to 2017)

With this series, the diagnostics indicator LEDs have been removed. Instead the Power Button state now gives a blink and color shift pattern to indicate where it had a problem. You can identify these systems by the fact that there is no Diagnostics LED block on the front of the unit.

2014 to 2017 Precision series

Power Button LED State Description
Power LED off Off Power is Off. LED is blank.
Power LED blinking amber Blinking Amber Initial State of LED at power-on. See the table below for Blinking Amber pattern diagnostic suggestions and possible failures.
Power LED solid amber Solid Amber The second state of the LED at power-on, indicates that the POWER_GOOD signal is active and it is probable that the power supply is fine.
Power LED blinking white Blinking White System is in a low-power state, either S1 or S3. This does not indicate a fault condition.
Power LED solid white Solid White System is in S0 state. This is the normal power states of a functioning machine. The BIOS turns the LED to this state to indicate it has started fetching op-codes.
State State Name Power Light:
Amber Blinking
Amber Blinking Pattern Problem Description Suggested Resolution
- - 2, 1 2 blinks followed by a short pause, 1 blink, long pause, then repeats Bad Motherboard
  • Contact Tech Support to troubleshoot the motherboard
- - 2, 2 2 blinks followed by a short pause, 2 blinks, long pause, then repeats Bad Motherboard, Power Supply, or Power Supply cabling
  • If you can assist to troubleshoot, narrow down the issue with PSU BIST Test, reseat cable.
  • If nothing works, contact Tech Support
- - 2, 3 2 blinks followed by a short pause, 3 blinks, long pause, then repeats Bad Motherboard, Memory, or Processor
  • If you can assist to troubleshoot, narrow down the issue by reseating memory and swapping a known good memory if available.
  • If nothing works, contact Tech Support
- - 2, 4 2 blinks followed by a short pause, 4 blinks, long pause, then repeats Bad coin-cell battery
  • If you can assist to troubleshoot, narrow down the issue by swapping a known good coin-cell battery if available.
  • If nothing works, contact Tech Support
S1 RCM 2, 5 2 blinks followed by a short pause, 5 blinks, long pause, then repeats BIOS Checksum Failure
  • System is in Recovery Mode.
  • Flash latest BIOS version. If problem persists, contact Tech Support
S2 CPU 2, 6 2 blinks followed by a short pause, 6 blinks, long pause, then repeats Bad Processor
  • CPU configuration activity is in progress, or a CPU failure was detected.
  • Contact Tech Support
S3 MEM 2, 7 2 blinks followed by a short pause, 7 blinks, long pause, then repeats Memory failures
  • Memory subsystem configuration activity is in progress. Appropriate memory modules were detected, but a memory failure has occurred.
  • If you can assist to troubleshoot, narrow down the issue with reseating memory and swapping a known good memory if available.
  • If nothing works, contact Tech Support.
S4 PCI 3, 1 3 blinks followed by a short pause, 1 blink, long pause, then repeats PCI Device or Video subsystem failures
  • PCI device configuration activity is in progress, or PCI device failure was detected.
  • If you can assist to troubleshoot, narrow down the issue by reseating PCI card and removing one by one to determine which card failed.
  • Contact Tech Support.
S5 VID 3, 2 3 blinks followed by a short pause, 2 blinks, long pause, then repeats Video Subsystem failure
  • Video subsystem configuration activity in progress or video subsystem failure.
  • If customer can assist to troubleshoot, narrow down the issue by removing one by one to determine which card failed.
  • Contact Tech Support.
S6 STO 3, 3 3 blinks followed by a short pause, 3 blinks, long pause, then repeats No Memory detected
  • If customer can assist to troubleshoot, narrow down the issue by removing one by one memory to determine which one failed and swapping to a known good memory if available to confirm.
  • Contact Tech Support.
S7 USB 3, 4 3 blinks followed by a short pause, 4 blinks, long pause, then repeats Storage Subsystem failure
  • Possible storage device configuration in progress or storage subsystem failure.
  • If you can assist to troubleshoot, narrow down the issue by removing one by one the storages on motherboard to determine which one failed.
  • Contact Tech Support.
S8 MEM 3, 5 3 blinks followed by a short pause, 5 blinks, long pause, then repeats Memory configuration or incompatible error
  • Memory subsystem configuration activity is in progress. No memory modules were detected.
  • If customer can assist to troubleshoot, narrow down the issue by removing one by one the memory on motherboard to determine which one failed. Also, combining the configuration to validate appropriate combination.
  • Contact Tech Support
S9 MBF 3, 6 3 blinks followed by a short pause, 6 blinks, long pause, then repeats System board failure
  • Fatal system board failure detected.
  • If customer can assist to troubleshoot, narrow down the issue by removing one by one the component on motherboard to determine which one failed.
  • If you identified any of the components failed, replace the component.
  • Contact Tech Support
S10 MEM 3, 7 3 blinks followed by a short pause, 7 blinks, long pause, then repeats Possible memory failure
  • Memory subsystem configuration activity is in progress. Memory modules have been detected but appear to be incompatible or in an invalid configuration.
  • If customer can assist to troubleshoot, narrow down the issue by removing one by one the memory on motherboard to determine which one failed.
  • Contact Tech Support.

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Diagnostic LEDs for the Precision series (2012 to 2013)

With this series, the Diagnostic LEDs changed to include a combination of the Power button LED state and the diagnostic LED indicators. The Diagnostic LEDs remain 1, 2, 3, 4, and placed on the front of the unit. You could identify these systems by their flat black and recessed Grill on the front face.

2012 to 2013 Precision series

Note: There are three types of color for the Power LED: Green, Blue, or White depending on the system model.
Power Button LED State Description
Power LED off Off Power is Off. LED is blank.
Power LED blinking amber Blinking Amber Initial State of LED at power-on. See the table below for Blinking Amber pattern diagnostic suggestions and possible failures.
Power LED solid amber Solid Amber The second state of the LED at power-on, indicates that the POWER_GOOD signal is active and it is probable that the power supply is fine.
Power LED blinking white Blinking White System is in a low-power state, either S1 or S3. This does not indicate a fault condition.
Power LED solid white Solid White System is in S0 state. This is the normal power states of a functioning machine. The BIOS turns the LED to this state to indicate it has started fetching op-codes.

Precision Diagnostic LEDs example

Note: Diagnostic LEDs can be either Green or Amber depending on the model type, but is always either off, flashing, or solid on.
State LED Pattern
( 1 2 3 4 )
LED Description Power LED State Assignment State Description
Pb0a Off Off Power LED off System Unplugged System is not plugged into AC, PSU is not plugged into system board, or control panel not connected to system board.
Pb0b Off Off Power LED solid white ACPI S0; Normal Operation System is on with no failures detected. This is a BIOS-controlled state and is also S0e.
Pb0c Off Off Power LED blinking white ACPI S1 Windows Standby State.
Pb1 Off Off Power LED off ACPI S4 or S5 Hibernate or Soft off. System plugged in, but either turned off or in Windows Hibernation State.
Pb2 3 solid 3 - Solid - Reserved Reserved
Pb3 3 and 4 solid 3,4 - Solid Power LED blinking white ACPI S3 Suspend to RAM Windows Standby State.
Pb4 2 solid 2 - Solid - Reserved Reserved
Pb5 2 and 4 solid 2,4 - Solid - Reserved Reserved
Pb6 2 and 3 solid 2,3 - Solid - Reserved Reserved
Pb7 2 3 and 4 flashing on 2,3,4 - Flashing On Power LED solid amber ACPI S0, hand off to BIOS control System on. BIOS not execution. This is the transition state to POST states.
Pb8 1 solid 1 - Solid - Reserved Reserved
Pb9 1 and 4 flashing on 1,4 - Flashing On Power LED solid amber Non-System board Regulator Failure A power failure has been detected on a plug-in component such as VRM, Video Riser, or Memory Riser.
Pb10 1 and 3 flashing on 1,3 - Flashing On Power LED blinking amber PSU Failure PSU may be bad, or PSU cable may be crimped creating a short on a main power rail. (PS_ON asserted, PS_PWRGOOD not asserted)
Pb11 1 3 and 4 flashing on 1,3,4 - Flashing On Power LED solid amber PSU Cable Failure All PSU cables may not be properly connected to system board. (PS_ON asserted, missing a main power rail)
Pb12 1 and 2 flashing on 1,2 - Flashing On Power LED solid amber System board Regulator Failure A power failure has been detected in one of the onboard system board regulators. This could be caused by a failed system board component or by a plug-in device creating a short on a regulated power rail. (PS_ON asserted, PS_PWRGOOD asserted, SYS_PWRGOOD de-asserted)
Pb13 1 2 and 4 flashing on 1,2,4 - Flashing On Power LED off Mismatch Hardware detected a population incompatibility with a critical system component such as CPU, VRM, PSU, or MEMORY RISER.
Pb14 1 2 and 3 solid 1,2,3 - Solid - Reserved Reserved
Pb15 1 2 3 4 solid 1,2,3,4 - Solid - Reserved Reserved
State LED pattern
( 1 2 3 4 )
LED Description State Name State assignment State description Suggested Resolution
S0a Off Off OFF OFF Power LED Off. No power is supplied to the system.
  • If the LEDs came on and then went off, look at troubleshooting the display and the operating system.
  • If the LEDs never came on at any point, then look into a power issue.
S0e Off Off ON Normal Operation, ACPI S0 Power LED Solid Green/Blue or White. System has successfully booted and is operating normally.  
S1 4 solid 4 RCM System is in Recovery Mode BIOS checksum failure was detected, and the system is now in recovery mode.
  • Reset the BIOS and clear the NVRAM
  • If this occurred after Windows updates, check your startup was not corrupted.
S2 3 solid 3 CPU CPU CPU configuration activity is in progress, or a CPU failure was detected.
  • Disconnect all devices and configure PC down to PSU, Motherboard, and CPU
  • If fault continues contact your technical support
  • If fault stops, plug disconnected parts back one at a time until fault recurs. Contact your technical support to take this further.
S3 3 and 4 solid 3,4 MEM Memory Memory subsystem configuration activity is in progress. Appropriate memory modules were detected, but a memory failure has occurred.
  • Remove all memory from the computer, does the LED code change?
  • If it does not, contact your technical support
  • If it does, add the memory modules back one at a time until the fault recurs, test that module in another slot and contact your technical support
S4 2 solid 2 PCI PCI device PCI device configuration activity is in progress, or PCI device failure was detected.
  • Remove all devices and all internal PCI devices
  • If fault continues contact your technical support
  • If fault stops, add parts back one at a time until fault recurs and contact your technical support
S5 2 and 4 solid 2,4 VID Video Card Video subsystem configuration activity in progress or video subsystem failure.
  • Ensure that the video cable is connected to the correct port
  • Reseat any add-in graphics cards
  • If the fault continues, remove any add-in graphics cards and test with known good monitor and video cable
  • Contact your technical support once you know which part the fault follows
S6 2 and 3 solid 2,3 STO Storage Storage device configuration in progress or storage subsystem failure.
  • Reseat the cables from the hard drives to the motherboard
  • If the fault continues, try substituting a known good hard drive into the system and contact your technical support
S7 2 3 and 4 solid 2,3,4 USB USB USB subsystem configuration activity in progress or USB subsystem failure.
  • Remove all devices and any internal CRUs
  • If LEDs change, add parts back one at a time until fault recurs and contact your technical support
  • If fault remains the same with parts removed, contact your technical support
S8 1 solid 1 MEM Memory Memory subsystem configuration activity is in progress. No memory modules were detected.
  • Reseat all memory modules
  • If fault continues, try the memory in different slots and contact your technical support
S9 1 and 4 solid 1,4 MBF System board Fatal system board failure detected.
  • Contact your technical support
S10 1 and 3 solid 1,3 MEM Memory Memory subsystem configuration activity is in progress. Memory modules have been detected but appear to be incompatible or in an invalid configuration.
  • Reset the BIOS and clear the NVRAM and any previous errors
  • Remove all memory from the computer. This includes any graphics cards. Does the LED code change?
  • If it does not, contact your technical support
  • If it does, add the parts back one at a time until the fault recurs, test that part in another slot and contact your technical support
S11 1 3 and 4 solid 1,3,4 PRV Other pre-video activity Indicates routine system activity preceding video initialization.
  • Remove all devices and any internal CRUs
  • If LEDs change, add parts back one at a time until fault recurs and contact your technical support
  • If fault remains the same with parts removed, contact your technical support
S12 1 and 2 solid 1,2 CFG Resource configuration System resource configuration in progress.
  • Reset the BIOS and clear the NVRAM and any previous errors
  • Remove all devices
  • If LEDs change, add parts back one at a time until fault recurs and contact your technical support
  • If fault remains the same with parts removed, contact your technical support
S13 1 2 and 4 solid 1,2,4   Reserved Reserved for future use. This pattern is being considered to indicate the Visual Off state on the Dimension systems.
  • Reserved
S14 1 2 and 3 solid 1,2,3 POV Other post-video activity Indicates routine system activity after video initialization.
  • Troubleshoot as per the error message on-screen
S15 1 2 3 and 4 solid 1,2,3,4 STD Boot hand off Indicates End of POST process. LEDs are normally in this state briefly as POST completes. Once the hand-off to the operating system is done, the LEDs turn off and transition to S0e state.
  • The Power On Self-Test has passed all checks
  • Troubleshoot the hard drive and the Operating System

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Diagnostic LEDs for the Precision series (2010 to 2011)

This series had a combination of Power button LED states with the diagnostic LEDs 1, 2, 3, 4. The diagnostics LEDs are on the front of the chassis.

2010 to 2011 Precision series

Note: There are two types of color for the Power LED: Green or Blue depending on the system model.
Off Blinking Amber Solid Amber Solid Green Blinking Green
Power LED off Power LED blinking amber Power LED solid amber Power LED solid green Power LED blinking green
Light Pattern Problem
Description
Suggested Resolution
Diagnostic LEDs Power
Button LED
 
Off Power LED off The computer is either turned off or not receiving power.
  • Reseat the power cable in the power connector on the back of the computer and the electrical outlet.
  • Bypass power strips, power extension cables, and other power protection devices to verify that the computer turns on properly.
  • Ensure that any power strips being used are plugged into an electrical outlet and are turned on.
  • Ensure that the electrical outlet is working by testing it with another device, such as a lamp.
  • Ensure that the main power cable and front panel cable are securely connected to the system board.
3 on Power LED off A possible system board failure has occurred.
  • Unplug the computer. Allow one minute for the power to drain. Plug the computer into a working electrical outlet and press the power button.
1 and 3 on Power LED blinking amber
Blinking
A possible system board, power supply, or peripheral failure has occurred.
  • Power off computer, leaving the computer plugged in. Press and hold the power supply test button on the rear of the power supply unit. If the LED next to the switch illuminates, the problem may be with your system board.
  • If the LED next to the switch does not illuminate, disconnect all internal and devices, and press and hold the power supply test button. If it illuminates, there could be a problem with a peripheral.
  • If the LED still does not illuminate, remove the PSU connections from the system board, then press and hold the power supply button. If it illuminates, there could be a problem with the system board.
  • If the LED still does not illuminate, the problem is probably with the power supply.
1 2 and 4 on Power LED solid amber No CPU present.
  • Reinstall the CPU and restart the system. If the computer still fails to boot, inspect the CPU socket for damage.
3 and 4 on Power LED solid amber Memory modules are detected, but a memory power failure has occurred.
  • If two or more memory modules are installed, remove the modules, then reinstall one module and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error. If only one memory module is installed, try moving it to a different DIMM connector and restart the computer.
  • If available, install verified working memory of the same type into your computer.
2 and 3 on Power LED solid amber A possible CPU or system board failure has occurred.
  • Replace the CPU with a known good CPU. If the computer still fails to boot, inspect the CPU socket for damage.
2 3 and 4 on Power LED solid amber BIOS may be corrupt or missing.
  • The computer hardware is operating normally, but the BIOS may be corrupt or missing.
1 on Power LED solid amber A possible system board failure has occurred.
  • Remove all peripheral cards from the PCI and PCI-E slots and restart the computer. If the computer boots, add the peripheral cards back one by one until you find the bad one.
1 and 4 on Power LED solid amber Power connector not installed properly.
  • Reseat the 2x2 power connector from the power supply unit.
2 on Power LED solid amber Possible peripheral card or system board failure has occurred.
  • Remove all peripheral cards from the PCI and PCI-E slots and restart the computer. If the computer boots, add the peripheral cards back one by one until you find the bad one.
1 and 2 on Power LED solid amber A possible system board failure has occurred.
  • Disconnect all internal and devices, and restart the computer. If the computer boots, add the peripheral cards back one by one until you find the bad one.
  • If the problem persists, the system board is probably bad.
1 2 and 3 on Power LED solid amber A possible coin-cell battery failure has occurred.
  • Remove the coin-cell battery for one minute, reinstall the battery, and restart.
Off Power LED solid blue The computer is in a normal on condition. The diagnostic lights are not lit after the computer successfully boots to the operating system.
  • Ensure that the display is connected and powered on.
3 on Power LED solid blue A possible processor failure has occurred.
  • Reseat the processor.
3 and 4 on Power LED solid blue Memory modules are detected, but a memory failure has occurred.
  • If two or more memory modules are installed, remove the modules (see your service manual), then reinstall one module (see your service manual and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.
  • If available, install working memory of the same type into your computer.
2 and 4 on Power LED solid blue A possible graphics card failure has occurred.
  • Reseat any installed graphics cards.
  • If available, install a working graphics card into your computer.
2 and 3 on Power LED solid blue A possible floppy drive or hard drive failure has occurred.
  • Reseat all power and data cables.
2 3 and 4 on Power LED solid blue A possible USB failure has occurred.
  • Reinstall all USB devices and check all cable connections.
1 on Power LED solid blue No memory modules are detected.
  • If two or more memory modules are installed, remove the modules (see your service manual), then reinstall one module (see your service manual) and restart the computer. If the computer starts normally, continue to install additional memory modules (one at a time) until you have identified a faulty module or reinstalled all modules without error.
  • If available, install working memory of the same type into your computer.
1 and 3 on Power LED solid blue Memory modules are detected, but a memory configuration or compatibility error has occurred.
  • Ensure that no special requirements for memory module/connector placement exist.
  • Ensure that the memory you are using is supported by your computer.
1 and 2 on Power LED solid blue A possible expansion card failure has occurred.
  • Determine if a conflict exists by removing an expansion card (not a graphics card) and restarting the computer.
  • If the problem persists, reinstall the card you removed, then remove a different card and restart the computer.
  • Repeat this process for each expansion card installed. If the computer starts normally, troubleshoot the last card removed from the computer for resource conflicts.
1 3 and 4 on Power LED solid blue A possible system board resource and/or hardware failure has occurred.
  • Clear CMOS.
  • Disconnect all internal and devices, and restart the computer. If the computer boots, add the peripheral cards back one by one until you find the bad one.
  • If the problem persists, the system board or system board component is probably bad.
1 2 and 3 on Power LED solid blue Another failure has occurred.
  • Ensure that all hard drive and optical drive cables are properly connected to the system board.
  • If there is an error message on the screen identifying a problem with a device (such as the floppy drive or hard drive), check the device to confirm that it is functioning properly.
  • If the operating system is attempting to boot from a device (such as the floppy drive or optical drive), check system setup to ensure the boot sequence is correct for the devices installed on your computer.

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Diagnostic LEDs and Beep Codes for the Precision series (Prior to 2009)

Dell Precision systems have a long history of built-in diagnostic indicators. These can be audible beeps and specific diagnostics LEDs to indicate when during the Power On Self-Test (POST) a system is having issues.

These models had a block of 1, 2, 3, 4, LEDs on the front of the chassis that either lit up Green or were off. A table below is included below with what these indicated. These models were primarily Tower Systems.

Precision series prior to 2009

Example of diagnostic LEDs

LED Pattern
(1 2 3 4)
LED
Pattern
State
Name
State
Description
Suggested Resolution
Off Off Off System POST complete — LED time-out has occurred
  • If the LEDs came on and then went off, look at troubleshooting the display and the operating system.
  • If the LEDs never came on at any point, then look into a power issue.
4 on 4 RCM BIOS checksum failure — Recovery mode
  • Reset the BIOS and clear the NVRAM
  • If this occurred after Windows updates, check that your startup was not corrupted.
3 on 3 CPU CPU configuration activity or failure; CPU Cache failure
  • Disconnect all devices and configure the computer down to PSU, Motherboard, and CPU
  • If fault continues contact your technical support
  • If fault stops, plug disconnected parts back one at a time until fault recurs. Contact your technical support to take this further.
3 and 4 on 34 MEM Memory subsystem configuration activity or failure
  • Remove all memory from the computer, does the LED code change?
  • If it does not, contact your technical support
  • If it does, add the memory modules back one at a time until the fault recurs, test that module in another slot and contact your technical support
2 on 2 PCI PCI device configuration or failure
  • Remove all devices and all internal PCI devices
  • If fault continues contact your technical support
  • If fault stops, add parts back one at a time until fault recurs and contact your technical support
2 and 4 on 2 4 VID Video subsystem configuration or failure
  • Ensure that the video cable is connected to the correct port
  • Reseat any add-in graphics cards
  • If fault continues, remove any add-in graphics cards and test with known good monitor and video cable
  • Contact your technical support once you know which part the fault follows
2 and 3 on 23 STO Storage device configuration or failure
  • Reseat the cables from the hard drives to the motherboard
  • If fault continues try substituting a known good hard drive into the system and contact your technical support
2 3 and 4 on 234 USB USB subsystem configuration activity or failure
  • Remove all devices and any internal CRUs
  • If LEDs change, add parts back one at a time until fault recurs and contact your technical support
  • If fault remains the same with parts removed, contact your technical support
1 on 1   No memory detected
  • Reseat all memory modules
  • If fault continues, try the memory in different slots and contact your technical support
1 and 4 on 1 4 MBF Fatal system board failure detected
  • Contact your technical support
1 and 3 on 1 3   Memory is detected, configuration, or compatibility error
  • Reset the BIOS and clear the NVRAM and any previous errors
  • Remove all memory from PC, This includes any graphics cards. Does the LED code change?
  • If it does not, contact your technical support
  • If it does, add the parts back one at a time until the fault recurs, test that part in another slot and contact your technical support
1 3 and 4 on 1 34 PRV Indicates system activity preceding video initialization
  • Remove all devices and any internal CRUs
  • If LEDs change, add parts back one at a time until fault recurs and contact your technical support
  • If fault remains the same with parts removed, contact your technical support
1 and 2 on 12 CFG System resource configuration
  • Reset the BIOS and clear the NVRAM and any previous errors
  • Remove all devices
  • If LEDs change, add parts back one at a time until fault recurs and contact your technical support
  • If fault remains the same with parts removed, contact your technical support
1 2 and 4 on 12 4   Reserved
  • Reserved
1 2 and 3 on 123 POV POST complete — Onscreen error message
  • Troubleshoot as per the error message on-screen
1 2 3 and 4 on 1234 STD POST complete — operating system hand-off complete
  • The Power On Self-Test has passed all checks
  • Troubleshoot the hard drive and the Operating System
Beep Code Description Suggested Resolution
1-1-2 CPU register test in progress Contact Technical Support
1-1-3 CMOS read/write test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
1-1-4 BIOS ROM checksum in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
1-2-1 Timer Test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
1-2-2 DMA initialization in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
1-2-3 DMA page register read/write test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
1-3-1 RAM refresh verification in progress or failure Troubleshoot the memory and memory slots.
1-3-2 1st 64K RAM test in progress or failure Troubleshoot the memory and memory slots.
1-3-3 1st 64K RAM chip or data line failure (multi bit) Troubleshoot the memory and memory slots.
1-3-4 1st 64K RAM odd/even logic failure Troubleshoot the memory and memory slots.
1-4-1 1st 64K RAM address line failure Troubleshoot the memory and memory slots.
1-4-2 1st 64K RAM parity test in progress or failure Troubleshoot the memory and memory slots.
1-4-3 Fail-safe timer test in progress Troubleshoot the memory and memory slots.
1-4-4 Software NMI port test in progress Troubleshoot the memory and memory slots.
2-1-1 1st 64K RAM chip or data line failure - bit 0 Troubleshoot the memory and memory slots.
2-1-2 1st 64K RAM chip or data line failure - bit 1 Troubleshoot the memory and memory slots.
2-1-3 1st 64K RAM chip or data line failure - bit 2 Troubleshoot the memory and memory slots.
2-1-4 1st 64K RAM chip or data line failure - bit 3 Troubleshoot the memory and memory slots.
2-2-1 1st 64K RAM chip or data line failure - bit 4 Troubleshoot the memory and memory slots.
2-2-2 1st 64K RAM chip or data line failure - bit 5 Troubleshoot the memory and memory slots.
2-2-3 1st 64K RAM chip or data line failure - bit 6 Troubleshoot the memory and memory slots.
2-2-4 1st 64K RAM chip or data line failure - bit 7 Troubleshoot the memory and memory slots.
2-3-1 1st 64K RAM chip or data line failure - bit 8 Troubleshoot the memory and memory slots.
2-3-2 1st 64K RAM chip or data line failure - bit 9 Troubleshoot the memory and memory slots.
2-3-3 1st 64K RAM chip or data line failure - bit A Troubleshoot the memory and memory slots.
2-3-4 1st 64K RAM chip or data line failure - bit B Troubleshoot the memory and memory slots.
2-4-1 1st 64K RAM chip or data line failure - bit C Troubleshoot the memory and memory slots.
2-4-2 1st 64K RAM chip or data line failure - bit D Troubleshoot the memory and memory slots.
2-4-3 1st 64K RAM chip or data line failure - bit E Troubleshoot the memory and memory slots.
2-4-4 1st 64K RAM chip or data line failure - bit F Troubleshoot the memory and memory slots.
3-1-1 Secondary DMA register test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-1-2 Primary DMA register test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-1-3 Primary IMR test in progress or failure Contact Technical Support
3-1-4 Secondary IMR test in progress or failure Contact Technical Support
3-2-2 Interrupt vector loading in progress Contact Technical Support
3-2-4 Keyboard controller test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-3-1 CMOS power fail and checksum test in progress Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-3-2 CMOS Config info validation in progress Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-3-3 RTC/Keyboard controller not found Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-3-4 Screen memory test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-4-1 Screen initialization test in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-4-2 Screen retrace tests in progress or failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
3-4-3 Search for video ROM in progress Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
4-2-1 Timer tick interrupt test in progress or failure Contact Technical Support
4-2-2 Shut down test in progress or failure Contact Technical Support
4-2-3 Gate A20 failure Contact Technical Support
4-2-4 Unexpected interrupt in Protected Mode Contact Technical Support
4-3-1 RAM test in progress or failure above address 0FFFFh Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
4-3-2 No memory in Bank 0 Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
4-3-3 Interval Timer Channel 2 test in progress or failure Contact Technical Support
4-3-4 Time-Of-Day Clock test in progress or failure Contact Technical Support
4-4-1 Super I/O chip failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .
4-4-4 Cache test failure Run the Dell Diagnostics. For more information, reference Resolve Hardware Issues With Integrated and Online Diagnostics (SupportAssist ePSA, ePSA, or PSA Error Codes) .

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Glossary of Acronyms:

See the table for definitions of the acronyms within this article.

Acronym Definition
BIOS Basic Input/Output System
CFG Resource Configuration
CPU Central Processing Unit
DIMM Dual In-line Memory Module
DMA Direct Memory Access
EC Embedded Controller
HECI Host Embedded Controller Interface
LCD Liquid Crystal Display
LED Light Emitting Diode
MBF Motherboard Failure
MBIST Memory Built-in Self-Test
ME Management Engine
MEM Memory
NVRAM Non-Volatile Random Access Memory
PCI Peripheral Component Interconnect
POV Post-video Activity
PRV Pre-video Activity
PSU Power Supply Unit
RAM Random Access Memory
RCM Recovery Mode
ROM Read Only Memory
RTC Real Time Clock
S0 System Power State S0 - This is the Working State, where your Windows computer is awake.
S1 System Power State S1 - In this sleep state, the CPU is stopped, and your computer is in standby mode.
S2 System Power State S2 - This state is similar to S1 except that the CPU and system cache are lost because the processor loses power.
S3 System Power State S3 - In this state, data is saved to RAM, hard drives, and other hardware are shut down.
S4 System Power State S4 - In this state, RAM, and other data are saved to the hard disk.
S5 System Power State S5 - The System is off.
SBIOS Small Board Interface Operating System
SPI Serial Peripheral Interface
STD Boot Hand Off
STO Storage Device
TPM Trusted Platform Module
USB Universal Serial Bus
VID Video

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If you require further assistance, contact Dell Technical Support.

Additional Information

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Article Properties


Affected Product

Fixed Workstations

Last Published Date

20 Dec 2023

Version

9

Article Type

How To