Dell OptiPlex computers have a long history of integrated diagnostic indicators that provide important insight when a computer fails the Power On Self-Test (POST). These indicators can be audible beeps, power buttons that display different states and colors, specific diagnostic LEDs, or a combination of these.
This article is a reference guide to the codes available on each model and what those codes mean. You can use this guide as a starting point to find your own solution, or you can contact technical support for further help. If you do contact us, our technicians may ask for your diagnostic codes in order to better understand your issue.
With the latest series, the Power Button state now gives more accurate errors. Using a blink and color shift pattern to indicate where it has a problem.
Power Button LED | State | Description |
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Off | Power is Off. LED is blank. | |
Blinking Amber | This is the initial state of the LED at power-up. See the table below for Blinking Amber pattern diagnostic suggestions and possible failures. | |
Solid Amber | The second state of the LED at power-up indicates that the POWER_GOOD signal is active, the power supply is likely OK. | |
Blinking White | The computer is in a low-power state, either S1 or S3. This does not indicate a fault condition. | |
Solid White | The computer is in S0 state. This is the normal power state of a functioning machine. The BIOS turns the LED to this state to indicate it has started fetching op-codes. |
Power Light: Amber Blinking |
Amber Blinking Pattern | Problem Description | Suggested Resolution |
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1, 1 | One blink followed by a short pause, one blink then a long pause, then it repeats. | MBIST: TPM TPM Detection Failure |
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1, 2 | One blink followed by a short pause, two blinks, then a long pause, then it repeats. | MBIST: SPI Flash Unrecoverable SPI Flash Failure |
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1, 5 | One blink followed by a short pause, five blinks, then a long pause, then it repeats. | i-Fuse Failure EC unable to program i-Fuse |
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1, 6 | One blink followed by a short pause, six blinks, then a long pause, then it repeats. | EC internal Failure Generic catch-all for ungrateful EC code flow errors |
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2, 1 | two blinks followed by a short pause, one blink, long pause, then repeats. | CPU Failure |
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2, 2 | two blinks followed by a short pause, two blinks, long pause, then repeats. | Bad Motherboard, Power Supply, or Power Supply cabling |
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2, 3 | two blinks followed by a short pause, three blinks, long pause, then repeats. | No Memory/RAM detected |
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2, 4 | two blinks followed by a short pause, four blinks, long pause, then repeats. | Memory RAM Failure |
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2, 5 | two blinks followed by a short pause, five blinks, long pause, then repeats. | Invalid Memory is installed |
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2, 6 | two blinks followed by a short pause, six blinks, long pause, then repeats. | Motherboard/Chipset Error |
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2, 7 | two blinks followed by a short pause, seven blinks, long pause, then repeats. | LCD Failure - SBIOS message |
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2, 8 | two blinks followed by a short pause, eight blinks, long pause, then repeats. | LCD Failure - EC detection of Power Rail failure | |
3, 1 | three blinks followed by a short pause, one blink, long pause, then repeats. | RTC Power Failure CMOS Battery Failure |
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3, 2 | three blinks followed by a short pause, two blinks, long pause, then repeats. | PCI of Video card/chip Failure | |
3, 3 | three blinks followed by a short pause, three blinks, long pause, then repeats. | BIOS Recovery 1: Image not found |
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3, 4 | three blinks followed by a short pause, four blinks, long pause, then repeats. | BIOS Recovery 2: Image found but invalid |
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3, 5 | three blinks followed by a short pause, five blinks, long pause, then repeats. | Power Rail Failure: EC ran into a power sequencing failure. | |
3, 6 | three blinks followed by a short pause, six blinks, long pause, then repeats. | Paid SPI Volume Error |
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3, 7 | three blinks followed by a short pause, seven blinks, long pause, then repeats. | ME error. Timeout waiting on ME to reply to HECI message | |
4, 1 | four blinks followed by a short pause, one blink, long pause, then repeats. | Memory DIMM Power Rail Failure | |
4, 2 | four blinks followed by a short pause, two blinks, long pause, then repeats. | CPU Power cable connection issue |
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With this series, the diagnostics indicator LEDs were removed. Instead, the Power Button state gives a blink and color shift pattern to indicate where it had a problem. You can identify these computers by the fact that there is no Diagnostics LED block on the front of the unit.
Power Button LED | State | Description |
---|---|---|
Off | Power is Off. LED is blank. | |
Blinking Amber | This is the initial state of the LED at power-up. See the table below for Blinking Amber pattern diagnostic suggestions and possible failures. | |
Solid Amber | The second state of the LED at power-up indicates that the POWER_GOOD signal is active, the power supply is likely OK. | |
Blinking White | The computer is in a low-power state, either S1 or S3. This does not indicate a fault condition. | |
Solid White | The computer is in S0 state. This is the normal power state 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 |
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- | - | 2, 1 | two blinks followed by a short pause, one blink, long pause, then repeats. | Bad Motherboard |
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- | - | 2, 2 | two blinks followed by a short pause, two blinks, long pause, then repeats. | Bad Motherboard, Power Supply, or Power Supply cabling |
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- | - | 2, 3 | two blinks followed by a short pause, three blinks, long pause, then repeats. | Bad Motherboard, Memory, or Processor |
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- | - | 2, 4 | two blinks followed by a short pause, four blinks, long pause, then repeats. | Bad coin-cell battery |
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S1 | RCM | 2, 5 | two blinks followed by a short pause, five blinks, long pause, then repeats. | BIOS Checksum Failure |
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S2 | CPU | 2, 6 | two blinks followed by a short pause, six blinks, long pause, then repeats. | Bad Processor |
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S3 | MEM | 2, 7 | two blinks followed by a short pause, seven blinks, long pause, then repeats. | Memory failures |
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S4 | PCI | 3, 1 | three blinks followed by a short pause, one blink, long pause, then repeats. | PCI Device or Video subsystem failures |
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S5 | VID | 3, 2 | three blinks followed by a short pause, two blinks, long pause, then repeats. | Video Subsystem failure |
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S6 | STO | 3, 3 | three blinks followed by a short pause, three blinks, long pause, then repeats. | No Memory detected |
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S7 | USB | 3, 4 | three blinks followed by a short pause, four blinks, long pause, then repeats. | Storage Subsystem failure |
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S8 | MEM | 3, 5 | three blinks followed by a short pause, five blinks, long pause, then repeats. | Memory configuration or incompatible error |
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S9 | MBF | 3, 6 | three blinks followed by a short pause, six blinks, long pause, then repeats. | System board failure |
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S10 | MEM | 3, 7 | three blinks followed by a short pause, seven blinks, long pause, then repeats. | Possible memory failure |
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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 computers by their flat black and gray front face.
Light Pattern | Problem Description |
Suggested Resolution | |
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Diagnostic LEDs | Power Button LED |
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The computer is either turned off or not receiving power. |
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A possible system board failure has occurred. |
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Blinking |
A possible system board, power supply, or device failure has occurred. |
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No CPU present |
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Memory modules are detected, but a memory power failure has occurred. |
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A possible CPU or system board failure has occurred. |
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BIOS may be corrupt or missing. |
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A possible system board failure has occurred. |
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The power connector is not installed properly. |
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A possible adapter card or system board failure has occurred. |
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A possible system board failure has occurred. |
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A possible coin-cell battery failure has occurred. |
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The computer is in a normal on condition. The diagnostic lights are not lit after the computer successfully boots to the operating system. |
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A possible processor failure has occurred. |
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Memory modules are detected, but a memory failure has occurred. |
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A possible graphics card failure has occurred. |
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A possible floppy drive or hard drive failure has occurred. |
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A possible USB failure has occurred. |
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No memory modules are detected. |
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Memory modules are detected, but a memory configuration or compatibility error has occurred. |
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A possible expansion card failure has occurred. |
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A possible system board resource or hardware failure has occurred. |
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Another failure has occurred. |
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This series had a combination of Power button LED states, and the A, B, C, D block was replaced with 1, 2, 3, 4 instead. The diagnostics LEDs moved from the rear of the chassis to the front under the audio ports. You could identify these models by their flat black front face and gray side panels and lids.
Off | Blinking Amber | Solid Amber | Solid Green | Blinking Green |
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The computer does not appear to get power from the Power Source. | The PSU is receiving power from the Source but is unable to distribute it. | The PSU is working, but the computer does not process data. | The computer processes data and has begun POST tests. (See the diagnostic LEDs) | The computer is in a hibernate or sleep state. |
LED Pattern (1 2 3 4) |
LED Pattern |
State Name |
State Description |
Suggested Resolution |
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Off | Off | System POST complete—LED time-out has occurred. |
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4 | RCM | BIOS checksum failure—Recovery mode |
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3 | CPU | CPU configuration activity or failure; CPU Cache failure |
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34 | MEM | Memory subsystem configuration activity or failure |
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2 | PCI | PCI device configuration or failure |
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2 4 | VID | Video subsystem configuration or failure |
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23 | STO | Storage device configuration or failure |
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234 | USB | USB subsystem configuration activity or failure |
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1 | No memory detected |
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1 4 | MBF | Fatal system board failure detected | ||
1 3 | Memory is detected; configuration or compatibility error. |
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1 34 | PRV | Indicates computer activity preceding video initialization |
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12 | CFG | System resource configuration |
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12 4 | Reserved |
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123 | POV | POST complete—Onscreen error message |
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1234 | STD | POST complete—operating system hand-off complete |
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This series had a block of four LEDs (A, B, C, and D) on the back of the chassis that lit up in green and amber. The table below describes what these LEDs indicated. These models were readily identifiable by their rounded fronts and clamshell assembly.
CPU configuration activity or failure; CPU Cache failure
LED Pattern |
State Name |
State Description |
Suggested Resolution |
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No Pattern Visible | Off | System POST complete - LED time-out has occurred. |
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ABCD | RCM | BIOS checksum failure - Recovery mode |
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ABCD | CPU |
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ABCD | MEM | Memory subsystem configuration activity or failure |
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ABCD | PCI | PCI device configuration or failure |
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ABCD | VID | Video subsystem configuration or failure |
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ABCD | STO | Storage device configuration or failure |
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ABCD | USB | USB subsystem configuration activity or failure |
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ABCD | No memory detected |
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ABCD | MBF | Fatal system board failure detected | |
ABCD | Memory is detected; configuration or compatibility error. |
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ABCD | PRV | Indicates computer activity preceding video initialization |
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ABCD | CFG | System resource configuration |
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ABCD | Reserved |
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ABCD | POV | POST complete—Onscreen error message |
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ABCD | STD | POST complete—operating system hand-off complete |
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In addition to the various types of diagnostics LEDs, there are several audible beep codes across all the models of these computers.
These codes are recognized across manufacturers and have remained the same for some time.
The key to these codes is displayed in the table below.
Diagnostic Beep Codes | ||
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Code | Cause | Suggested Resolution |
1-1-2 | Microprocessor register failure | Contact Technical Support. |
1-1-3 | NVRAM | Contact Technical Support. |
1-1-4 | ROM BIOS checksum failure | Contact Technical Support. |
1-2-1 | Programmable interval timer | Contact Technical Support. |
1-2-2 | DMA initialization failure | Contact Technical Support. |
1-2-3 | DMA page register read/write failure | Contact Technical Support. |
1-3-1 through 2-4-4 | DIMMs not being properly identified or used | See Dell Knowledge Base article How to Diagnose and Resolve Common Memory Issues on a Dell Desktop Computer. |
3-1-1 | Secondary DMA register failure | Contact Technical Support. |
3-1-2 | Primary DMA register failure | Contact Technical Support. |
3-1-3 | Primary interrupt mask register failure | Contact Technical Support. |
3-1-4 | Secondary interrupt mask register failure | Contact Technical Support. |
3-2-2 | Interrupt vector loading failure | Contact Technical Support. |
3-2-4 | Keyboard Controller test failure | Contact Technical Support. |
3-3-1 | NVRAM power loss | Contact Technical Support. |
3-3-2 | NVRAM configuration | Contact Technical Support. |
3-3-4 | Video Memory Test failure | Contact Technical Support. |
3-4-1 | Screen initialization failure | Contact Technical Support. |
3-4-2 | Screen retrace failure | Contact Technical Support. |
3-4-3 | Search for video ROM failure | Contact Technical Support. |
4-2-1 | No time tick | Contact Technical Support. |
4-2-2 | Shutdown 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 | Memory failure above address 0FFFFh | Contact Technical Support. |
4-3-3 | Timer-chip counter two failure. | Contact Technical Support. |
4-3-4 | Time-of-day clock stopped | Contact Technical Support. |
4-4-1 | Serial or parallel port test failure | Contact Technical Support. |
4-4-2 | Failure to decompress code to shadowed memory | Contact Technical Support. |
4-4-3 | Math co-processor test failure | Contact Technical Support. |
4-4-4 | Cache test failure | Contact Technical Support. |
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-integrated 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 personal 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 computer 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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