Stephen Harrison 🗓️ Updated ⏱️ — 📝 —


BIOS POST Beep Codes — Ultimate Diagnostic & Troubleshooting Guide

TL;DR — BIOS POST Beep Codes

  • BIOS POST Beep Codes mean the BIOS caught a hardware fault before the screen turns on. Count the pattern (e.g., “2 short, 1 long”), let it repeat, and write it down.
  • Cross-check your exact motherboard / PC manual and BIOS / UEFI version—OEMs often remap codes.
  • Refer to the Multi-table Beep Codes tool for guidance on specific beep codes and fix suggestions.
  • Work with your hardware components in the given order, i.re. RAM → CPU → GPU/Video → CMOS, changing one thing at a time. If needed, clear CMOS, check PSU stability, then use a POST / Diagnostic Card for deeper clues.
  • No beeps? You might not have a speaker fitted, or the system has failed too early to beep — If possible, fit a small 2-pin buzzer to the SPEAKER header and retest.

What You Will Learn About BIOS POST Beep Codes Today

  • What are BIOS beep codes and why they matter
  • BIOS / UEFI Beep Codes for different systems, what they mean and suggested actions to resolve
  • How to use the interactive AMI BIOS Beep Codes table and deep-dive troubleshooting guides for each beep pattern
  • The best approach to troubleshooting your BIOS error codes
  • Common gotchas and warnings when investigating BIOS beep codes
  • A brief look at Checkpoints and POST cards for more advanced POST troubleshooting
  • The answers to common questions people ask
  • Where to find further information for your system and official documentation

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Important Notice about BIOS Beep Codes

BIOS POST beep codes are emitted when a hardware fault is detected after your computer is first switched on. They will happen before anything appears on your screen, and they aim to help you determine which hardware component has failed.

The beep patterns vary between computer and motherboard manufacturer's, and vary between each instance of BIOS firmware released. In addition, computer manufacturers sometimes add further customisations to their flavour of AMIBIOS software.

Therefore, always check your OEMs official documentation and guidance so you have accurate information regarding their POST failure beep codes.


What Are BIOS POST Beep Codes and Why They Matter

When you switch on a PC, the BIOS firmware initiates the POST (Power‑On Self Test) sequence. This checks hardware components such as memory, CPU, video, etc., are all in working order. The POST is quick. It only takes a few seconds, so you need to be vigilant from the moment your PC is powered up.

If a critical fault occurs before anything can be displayed on your monitor, the BIOS makes a beep sound, via your system's speaker, to signify an error. This is your clue that a hardware fault exists. Assuming your graphics card is not at fault, the beep is accompanied by an error code or message on screen to help further identify the source of the problem.

Beep codes are the earliest indicator you have when diagnosing a hardware failure. It is therefore essential to have a reliable beep code reference table and a sensible troubleshooting approach, and I just happen to have these ready and waiting for you.


The AMIBIOS Evolution — Versions & Differences

American Megatrends has updated its “BIOS Core” or “UEFI platform”, over time, just like all good software houses do. AMIBIOS8, released in 2008, was superseded by Aptio v4, and then Aptio v5 standard.

Each of these versions, and the OEM customisations applied to these versions, all have a variation of the core set of AMI beep or signalling behaviours. 

  • AMIBIOS8 is the classic core used in older systems. The official “AMIBIOS8 Check Point & Beep Code List” is a key primary source.
  • Aptio 4 / Aptio V are UEFI‑based cores. They reference beep codes or status codes adapted for modern systems. The official “AMI Aptio V BIOS POST Codes List” is a key primary source.
  • Some OEMs and motherboard manufacturers add their beep schemes to the AMI firmware, so the generic AMI lists may not always fully match your system.

Because of these version differences, you should always cross‑reference with your specific motherboard manual or BIOS vendor documentation, so you have the right set of beep codes to hand.


The AMI BIOS Beep Codes Table & Beep Code Explanations

I have put together a very comprehensive and interactive table of BIOS / UEFI Beep Codes, with deep-drive troubleshooting guides for each beep pattern.

AMIBIOS, Award, Phoenix and Dell, HP, Mac to new a few are covered. Use the search bar to find the beep code you hear, click the sound icon to play the beep you hear, then the information icon for the troubleshooting guide.


BIOS POST Beep Codes Multi-Table SearchBIOS POST Beep Codes
BIOS POST Beep Codes Multi-Table Search

Troubleshooting Workflow — From Beep to Fix

Below is a general guide from when you first hear the POST beep error, to diagnosing the problem, then solving the issue:

Beep Code Troubleshooting — Clear, Linear Flow

Move top-to-bottom. From Step 4 onward, ask “Resolved?” If Yes → Continue reading. If No → keep going. Change one thing at a time.

Count & note the beep pattern

Listen carefully — long vs short can be subtle. Write down the exact sequence (e.g., 2 short, 1 long).

Continue → Step 2

Cross-check with OEM/motherboard manual & BIOS make/version

OEMs may remap codes. Use the board’s documentation as the prime reference for your exact BIOS/UEFI version.

Continue → Step 3

Check the BIOS/UEFI Beep Codes table

Verify the pattern and identify the suspected hardware at fault (e.g., RAM, CPU, GPU, CMOS).

Continue → Step 4

Clear CMOS / Reset BIOS settings

Use the reset jumper or temporarily remove the battery. This can recover from invalid/broken registers.

Resolved?
Yes → Continue reading No → Go to Step 7

Document your progress

Record which changes altered the beep behaviour. This minimises future guesswork and speeds up troubleshooting.

Tip: Keep changes minimal between tests — one variable at a time.

The idea behind this approach is to minimise guesswork, confusion, and wasted effort. The amount of time I have wasted over the years by simply diving into the fault, without a structured troubleshooting approach, would have saved me many hours of wasted effort.


Common BIOS POST Beep Codes Gotchas, OEM Variations & Warnings

  • OEM Overrides: Some motherboard manufacturers (e.g. Asus, MSI) modify beep code interpretations or use proprietary extensions. Always check the manual for your motherboard.
  • BIOS / UEFI Behavior: On modern UEFI BIOS, audible beep support may be removed or disabled — the system might instead log errors or display on your monitor.
  • Non‑standard Beep Combinations: Some rare motherboards use nonstandard beep sequences that do not match the classic list.
  • No Beep at All?
    • Speaker may be absent / not connected.
    • Power / motherboard is dead, so no BIOS is executing.
    • Early failure before even beep logic can run.
  • Continuous or Repeated Beeps: Sometimes used to indicate major memory or power faults. Generic AMIBIOS beep pattern lists often does not define these precisely.
  • Faulty Speaker / Jumper: The internal PC speaker or its wiring may be defective. Try replacing or testing with a known good speaker.
  • Partial vs Complete Memory Failure: A memory module may partially pass tests and produce misleading beeps — always swap/test modules.

Keep these hints and tips in mind, and you will avoid misdiagnosis based solely on beep counts only.

I recall working on a Dell computer that was giving two audible beeps at power on. The memory modules looked fine. I tested them in another computer, and they worked perfectly. When a put them back into the problematic computer, it booted without issue.

My lesson here was to double-check the memory modules are properly seated on the motherboard. If they are out even by a small margin, they will not work, even if by the naked eye they look seated properly. Follow the workflow above properly and do not skip any steps.


Using Checkpoints & POST Cards (Beyond Beeps)

For deeper debugging, AMI supports checkpoint output (I/O port 0×80) during BIOS execution. All this means is there are internal codes indicating which stage BIOS is in. A POST / diagnostic card can read these checkpoint codes, giving you far more insight into the exact issue, beyond simple beep patterns.

  • Checkpoint cards (POST cards) plug into PCI / ISA slots and display the hex value output at port 80h.
  • During the boot process, the BIOS will output checkpoint bytes until it reaches the fault. The last good checkpoint helps you narrow down where failure occurred.
  • The “AMIBIOS8 Check Point & Beep Code List” and “AMI Aptio V BIOS POST Codes List” provides mappings between checkpoint codes and BIOS stage / routine names.

However, not all motherboards or BIOS versions support visible checkpoint display; some hide or even disable it.

Using checkpoint cards is especially helpful when beeps are either ambiguous for your make / model of computer, or older / less popular motherboard manufacturer, or even when beep patterns are absent altogether.

The video below is one I made when using my POST card in one of my computers to show what happens after power on.

Although it is a little difficult to see clearly, this is what I observed:

  • Code 3387 displayed. This indicates a BIOS check is in progress;
  • Code 2900 displayed. This indicates the BIOS check is successful;
  • Code AA00 displayed. This indicates the Bootstrap process is successful, and the Operating System is loading successfully.

One of the downsides of this type of card is the 4 digit display is on the 'wrong side' to see it easily. Fortunately, it also has a 2 digit display on the opposite side which shows coded outcomes.


Video — POST Card in Action


FAQs — Simple Answers For Common Beep Code Problems — In Plain English

Below is a list of Frequently Asked Questions I have put together that are most searched for across the Internet, signifying many users have the same thoughts and queries regarding BIOS POST Beep Codes.

How do I count the beeps properly?
Short beeps are quick ticks. Long beeps last about 1 second. Many codes look like groups.
Example: 1-2-2 means 1 beep, pause, 2 beeps, pause, 2 beeps, then the whole thing repeats.
Let the pattern repeat twice so you’re sure what you heard. Write it down before you start fixing.
I hear no beeps at all. Is something wrong?
Maybe nothing is wrong — many PCs don’t include a tiny speaker. If your board has a “SPEAKER” header, plug in a cheap 2-pin buzzer. Without it, you won’t hear any beeps.
No beeps and no display. What should I try first?
Try a “minimal boot”:
  1. Turn off and unplug the PC. Check the big 24-pin and the CPU power cable are firmly in.
  2. Remove extra parts. Leave only the motherboard, CPU, one stick of RAM, and power supply.
  3. Add a speaker/buzzer if you have the header.
  4. Turn on. If still nothing, the fault may be the CPU or motherboard power circuits.
I get 1 short beep. Is that “all OK” or an error?
It depends on the exact BIOS and PC brand. Older AMI lists 1 short as a memory (refresh) error. Many newer PCs use 1 short beep to say “POST passed”. Check your model’s table to be sure.
Which beeps usually mean a graphics (video) problem?
Common signs are 1 long + 2 or 3 short or a “6 beeps” style code. Try this:
  • Turn off power. Reseat the graphics card.
  • Check the card’s power plugs.
  • If your CPU has built-in graphics, remove the card and try the monitor on the motherboard port.
How can I tell if the beeps point to bad RAM?
Rapid, repeating short beeps or patterns with 2–3–4 short beeps often point to memory. Fix steps:
  1. Power off. Reseat the RAM sticks.
  2. Test one stick at a time in the slot the manual recommends.
  3. Use the right type (for example, do not mix ECC/registered with standard desktop RAM).
AMI code with 10 short beeps — is my board dead?
Not always. On some AMI versions, 10 short beeps can mean a CMOS setting/register problem.
  1. Do a proper CMOS reset (see next FAQ).
  2. Replace the coin-cell battery (CR2032) if it’s old.
  3. If the code stays, the board’s CMOS circuit may be faulty.
How do I safely clear the CMOS?
  1. Turn off and unplug the PC.
  2. If your board has a CLR_CMOS button or jumper, use it (check the manual).
  3. No jumper? Remove the CR2032 battery for 5 minutes. Press the power button once while unplugged to drain power.
  4. Put the battery back. Power on. Choose “Load Defaults”, then set boot/storage options again.
Why don’t my beeps match some AMI tables I found online?
Big brands (Dell, HP, Lenovo, etc.) sometimes change the codes or use flashing lights instead. Always check the table for your exact model on the maker’s website.
It makes a siren sound or beeps nonstop. What does that mean?
That often means heat or CPU power problems.
  • Make sure the CPU fan is plugged into the CPU-FAN header.
  • Check the cooler is tight and has thermal paste.
  • If it overheats, turn off right away and fix cooling before trying again.
My PC only blinks lights. Can I still use this guide?
Yes. Count the blinks the same way you count beeps. Then look up the maker’s chart for your model. The fix steps (reseat RAM/GPU, clear CMOS, minimal boot) are the same.
Where do I find the right code list for my PC?
Look on the support page for your PC or motherboard model. Search for “beep codes” or “LED codes” plus your model name. For AMI-based boards, the maker’s manual usually includes the list.

References & Downloadable Official Documents

Review the list of high-quality and relevant references to support your BIOS POST Beep Codes journey

  1. AMI: AMIBIOS8 Check Point & Beep Code List PDF — he original core documentation for AMIBIOS8 beep and internal checkpoint codes. Open
  2. AMI Aptio V BIOS POST Codes List — he original core documentation for AMI Aptio Version 5. Open
  3. Thomas‑Krenn: AMI BIOS Beep Codes Overview — Contrasts AMIBIOS8 and Aptio versions. Open
  4. Lifewire: AMIBIOS Beep Code Troubleshooting Guide — User-friendly explanations of beep codes and fixes. Open
  5. RetroWeb (blog): AMIBIOS Beep & POST Codes List — Crowd‑compiled reference list. Open
  6. Supermicro / AMI Aptio 5.x Status Codes PDF — Example of modern UEFI code mapping for specific motherboard models. Open

BIOS POST Beep Codes — Ask A Question

Not sure about anything you have read on this web page?

Have a BIOS beep code that is not covered above?

Click the button below to ask me a question — include as much detail as you can, including the steps you have taken in the Troubleshooting workflow, and I'll do all I can to help get your machine working again.

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Key Takeaways (Summary)

  • Beep patterns vary by BIOS version and OEM. Always confirm with your motherboard / computer manual; do not rely on a generic AMI lists alone.
  • Check out the interactive, multivendor table (AMI, Award/Phoenix, Dell, HP, Mac, etc.) plus deep-dive guides for each pattern to move you from noise → diagnosis → fix.
  • Follow the linear workflow, i.e. Capture the beep pattern → confirm the issue in the multivendor table → apply the targeted fix → Resolve → Record changes for future reference.
  • Common gotchas include missing speakers, UEFI systems with beeps disabled, OEM-specific remaps, partial RAM failures that mislead diagnosis.
  • When beeps are ambiguous or absent, a POST / Checkpoint Card (port 80h codes) can pinpoint the failing stage — especially on less popular or tricky motherboards.

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