PC Won’t Boot? BIOS Beep Codes to the Rescue

If your PC won’t start up and doesn’t show an error message, it doesn’t mean your computer has nothing to say. BIOS beep codes, short sound patterns emitted during startup, offer vital clues about where hardware problems might lie.

What is BIOS?

BIOS (Basic Input/Output System) is the software built into your PC’s motherboard. When you turn your computer on, the BIOS runs a basic self-test (POST) to make sure your hardware components are functioning before handing things over to the operating system.

Common BIOS Beep Code Patterns

Different BIOS makers use specific beep patterns to signal errors. Here’s a breakdown of the most common codes:

Important: For an exhaustive list of codes, always consult your motherboard manual (usually available online)

AMI BIOS Beep Code Patterns

AMI (American Megatrends, Inc.) is a major BIOS manufacturer. If your computer uses an AMI BIOS, these beep codes can help you understand what problem is occurring during startup.

Beep Code PatternMeaning
1 Long BeepPOST has passed all tests – The system is booting properly. Everything should be OK and your computer should continue booting.
1 Short BeepDRAM refresh failure – The programmable interrupt timer or programmable interrupt controller has probably failed.
2 Short BeepsParity circuit failure – A memory parity error has occurred in the first 64K of RAM. The RAM IC is probably bad.
3 Short BeepsBase 64K RAM failure – A memory failure has occurred in the first 64K of RAM. The RAM IC is probably bad.
4 Short BeepsSystem timer failure – The system clock/timer IC has failed or there is a memory error in the first bank of memory.
5 Short BeepsProcess failure – The system CPU has failed.
6 Short BeepsKeyboard controller Gate A20 error – The keyboard controller IC has failed, which does not allow Gate A20 to switch the processor to protected mode.
7 Short BeepsVirtual mode exception error – The CPU has generated an exception error because of a fault in the CPU or motherboard circuitry.
8 Short BeepsDisplay memory Read/Write test failure – The system video adapter is missing or defective.
9 Short BeepsROM BIOS checksum failure – The contents of the system BIOS ROM do not match the expected checksum value. The BIOS ROM is probably defective and should be replaced.
10 Short BeepsCMOS shutdown Read/Write error – The shutdown for the CMOS has failed.
11 Short BeepsCache Memory error – The L2 cache is faulty.
1 Long, 2 Short BeepsFailure in video system – An error was encountered in the video BIOS ROM, or a horizontal retrace failure has been encountered.
1 Long, 3 Short BeepsConventional/Extended memory failure – A fault has been detected in memory above 64KB.
1 Long, 8 Short BeepsDisplay/Retrace test failed – The video adapter is either missing or defective.
Troubleshooting Tips
  • Focus on Likely Problems: RAM, keyboard, video issues, and serious CPU or BIOS errors are typically signaled by AMI beeps.
  • Basic Steps First:
    • Reseat components: RAM, video card (if dedicated)
    • Check connections: monitor, keyboard, mouse
    • Consider testing with alternate components, if possible
  • Look for Patterns: The code’s nature (short, long, repeating) helps narrow down the issue.
Important Notes:
  • Your Manual is Best: Your specific motherboard’s manual will have the most precise beep code list tailored to your system.
  • Severe Warnings: Beeps like 5 short (CPU) or 9 short (BIOS) can mean significant hardware problems. Professional assistance may be needed.

For additional solutions, see our troubleshooting tips here.

Award BIOS Beep Code Patterns

Award BIOS is another common BIOS manufacturer. If your computer uses Award BIOS, here’s a breakdown of beep codes that can help you troubleshoot startup issues:

Beep Code PatternMeaning
1 Long, 2 Short BeepsVideo adapter error – Indicates a video error has occurred and the BIOS cannot initialize the video screen to display any additional information.
1 Long, 3 Short BeepsNo video card or bad video RAM.
High-Frequency BeepsCPU Overheating.
Repeating (Endless Loop)Memory error.
Repeating High/LowCPU – Either the CPU is not seated properly or the CPU is damaged. This may also be due to excess heat.
Troubleshooting Tips:
  • Prioritize Common Culprits: Focus troubleshooting on your video card, RAM, and CPU, as these are most often indicated by Award BIOS beep codes.
  • Step-by-Step Checks:
    1. Reseat video card and RAM modules.
    2. Run memory tests if possible.
    3. Ensure your CPU fan is spinning correctly. Check BIOS for temperature and adjust fan settings if needed.
  • Consider Replacement: If basic troubleshooting fails, replacing faulty components (RAM, video card, potentially CPU) might be necessary.
Important Notes:
  • The manual is Key: Always consult your specific motherboard manual for the most accurate interpretation of beep codes for your system. Award BIOS code variations exist.
  • Severe Issues: Certain patterns may indicate serious issues with your motherboard. In these cases, seeking professional technical assistance is advisable.

For additional solutions, see our troubleshooting tips here.

AST BIOS Beep Code Patterns

AST BIOS uses a distinct set of beep codes to signal potential errors. Below is a guide to help you understand what those beeps mean:

Beep Code PatternMeaning
1 Long BeepDMA controller 0 failure – The DMA controller IC for channel 0 has failed.
1 Short BeepCPU register test failure – The CPU has failed.
2 Short BeepsKeyboard controller buffer failure – The keyboard controller has failed.
3 Short BeepsKeyboard controller reset failure – The keyboard controller has failed.
4 Short BeepsKeyboard communication failure – Either the keyboard controller IC or the associated circuitry has failed. Replace the keyboard first, then if it is still faulty, the keyboard controller has failed.
5 Short BeepsKeyboard input failure – The keyboard controller IC has failed.
6 Short BeepsSystem board chipset failure – The chipset on the motherboard has failed.
9 Short BeepsBIOS ROM checksum error – The BIOS ROM has failed.
10 Short BeepsSystem timer test failure – The system clock IC has failed.
11 Short BeepsSystem timer test failure – The system clock IC has failed.
12 Short BeepsCMOS RAM shutdown register failure – The real-time clock/CMOS IC failed.
1 Long, 1 Short BeepDMA controller 1 failure – The DMA controller IC for channel 1 has failed.
1 Long, 2 Short BeepsVideo vertical retrace failure – The video adapter has probably failed.
1 Long, 3 Short BeepsVideo memory test failure – The video adapter’s memory has failed.
1 Long, 4 Short BeepsVideo adapter failure – The video adapter has failed.
1 Long, 5 Short Beeps64KB memory failure – A failure has occurred in the base 64KB of memory.
1 Long, 6 Short BeepsUnable to load interrupt vectors – The BIOS was unable to load the interrupt vectors into memory.
1 Long, 7 Short BeepsUnable to initialize video – This is a video problem.
1 Long, 8 Short BeepsVideo memory failure – The is a failure in the video memory.
Troubleshooting Tips:
  • Check connections: Start with simple things like ensuring cables and components are properly seated.
  • Suspect RAM: Memory issues are often behind AST beep codes. Reseat RAM, and test with individual modules.
  • BIOS-related: Issues like a bad BIOS checksum may require specialized tools or technical support.

Important: Always consult your motherboard’s manual for the most accurate beep codes. AST codes can vary based on your specific system.

For additional solutions, see our troubleshooting tips here.

Dell Beep Code Patterns

Dell computers use a specific series of beeps to communicate hardware issues during startup. Refer to the table below to understand what these beep codes mean and start troubleshooting.

Beep Code PatternMeaning
1 BeepPossible motherboard failure / BIOS ROM corruption.
2 BeepsNo RAM detected.
3 BeepsMotherboard chipset error (Northbridge).
4 BeepsMemory (RAM) read/write failure.
5 BeepsReal-Time Clock (RTC) power failure.
6 BeepsVideo card/chip failure.
7 BeepsProcessor (CPU) failure.
Troubleshooting Tips:
  • Built-in Diagnostics: Many Dell systems have more comprehensive diagnostics built into the BIOS. Access these with keys like F12 during bootup for detailed hardware tests.
  • Service Tag: Your Dell’s unique Service Tag is invaluable for tailored support. Locate it on a sticker on your device.
  • Dell Support: Use Dell’s support site for targeted troubleshooting articles, manuals, and help: https://www.dell.com/support
Dell bios beep codes service tag sticker example
Dell Service Tag Sticker Example
Important Notes:
  • Model Specific: Always consult your specific Dell model’s documentation for the most accurate beep codes and diagnostic tools.
  • No Beeps: Lack of beeps might indicate deeper problems (power supply, processor, motherboard), likely requiring technical support.

For additional solutions, see our troubleshooting tips here.

Intel (Phoenix) Beep Code Patterns

Phoenix BIOS is commonly used in computers with Intel motherboards. These codes are a little more complicated. The BIOS emits three sets of beeps. For example, 1 -pause 3 -pause 3 -pause 3 -pause. This 1-3-3-3 combo and each set of beeps are separated by a brief pause. Knowing these beep codes helps troubleshoot startup issues.

Beep Code PatternMeaning
1-1-1-1Unconfirmed beep code. Reseat RAM chips or replace RAM chips as a possible solution.
1-1-1-3Verify real mode.
1-1-2-1Get CPU type.
1-1-2-3Initialize system hardware.
1-1-3-1Initialize chipset registers with initial POST values.
1-1-3-2Set in POST flag.
1-1-3-3Initialize CPU registers.
1-1-4-1Initialize cache to initial POST values.
1-1-4-3Initialize I/O.
1-2-1-1Initialize power management.
1-2-1-2Load alternate registers with initial POST values.
1-2-1-3Jump to UserPatch0.
1-2-2-1Initialize keyboard controller.
1-2-2-3BIOS ROM checksum.
1-2-3-18254 timer initialization.
1-2-3-38237 DMA (direct memory access) controller initialization.
1-2-4-1Reset programmable interrupt controller.
1-3-1-1Test DRAM refresh.
1-3-1-3Test 8742 keyboard controller.
1-3-2-1Set ES segment to register to 4 GB.
1-3-3-1Autosize DRAM.
1-3-3-3Clear 512 K base RAM.
1-3-4-1Test 512 base address lines.
1-3-4-3Test 512 K base memory
1-4-1-3Test CPU bus clock frequency.
1-4-2-4Reinitialize the chipset.
1-4-3-1Shadow system BIOS ROM.
1-4-3-2Reinitialize the cache.
1-4-3-3Autosize cache.
1-4-4-1Configure advanced chipset registers.
1-4-4-2Load alternate registers with CMOS (complementary metal-oxide semiconductor) values.
2-1-1-1Set initial CPU speed.
2-1-1-3Initialize interrupt vectors.
2-1-2-1Initialize BIOS interrupts.
2-1-2-3Check ROM Copyright notice.
2-1-2-4Initialize manager for PCI (Peripheral Component Interconnect) options ROMs.
2-1-3-1Check video configuration against CMOS.
2-1-3-2Initialize PCI bus and devices.
2-1-3-3Initialize all video adapters in the system.
2-1-4-1Shadow video BIOS ROM.
2-1-4-3Display Copyright notice.
2-2-1-1Display CPU type and speed.
2-2-1-3Test keyboard.
2-2-2-1Set key click if enabled.
2-2-2-3Enable keyboard.
2-2-3-1Test for unexpected interrupts.
2-2-3-3Display prompt Press F2 to enter SETUP.
2-2-4-1Test RAM between 512 and 640 k.
2-3-1-1Test expanded memory.
2-3-1-3Test extended memory address lines.
2-3-2-1Jump to UserPatch1.
2-3-2-3Configure advanced cache registers.
2-3-3-1Enable external and CPU caches.
2-3-3-3Display external cache size.
2-3-4-1Display shadow message.
2-3-4-3Display non-disposable segments.
2-4-1-1Display error messages.
2-4-1-3Check for configuration errors.
2-4-2-1Test real-time clock.
2-4-2-3Check for keyboard errors.
2-4-4-1Set up hardware interrupt vectors.
2-4-4-3Test coprocessor if present.
3-1-1-1Disable onboard I/O ports.
3-1-1-3Detect and install external RS232 ports.
3-1-2-1Detect and install external parallel ports.
3-1-2-3Re-initialize onboard I/O ports.
3-1-3-1Initialize BIOS data area.
3-1-3-3Initialize extended BIOS data area.
3-1-4-1Initialize floppy controller.
3-2-1-1Initialize hard disk controller.
3-2-1-2Initialize local bus hard disk controller.
3-2-1-3Jump to UserPatch2.
3-2-2-1Disable the A20 address line.
3-2-2-3Clear huge ES segment register.
3-2-3-1Search for option ROMs.
3-2-3-3Shadow option ROMs.
3-2-4-1Set up Power Management.
3-2-4-3Enable hardware interrupts.
3-3-1-1Set time of day.
3-3-1-3Check key lock.
3-3-3-1Erase F2 prompt.
3-3-3-3Scan for F2 keystroke.
3-3-4-1Enter CMOS setup.
3-3-4-3Clear in POST flag.
3-4-1-1Check for errors.
3-4-1-3POST done, prepare to boot the operating system.
3-4-2-1One beep.
3-4-2-3Check password (optional).
3-4-3-1Clear global descriptor table.
3-4-4-1Clear parity checkers.
3-4-4-3Clear screen (optional).
3-4-4-4Check virus and backup reminders.
4-1-1-1Try to boot with INT 19.
4-2-1-1Interrupt handler error.
4-2-1-3Unknown interrupt error.
4-2-2-1Pending interrupt error.
4-2-2-3Initialize option ROM error.
4-2-3-1Shutdown error.
4-2-3-3Extended block move.
4-2-4-1Shutdown 10 error.
4-3-1-3Initialize the chipset.
4-3-1-4Initialize refresh counter.
4-3-2-1Check for forced flash.
4-3-2-2Check the HW status of the ROM.
4-3-2-3BIOS ROM is OK.
4-3-2-4Do a complete RAM test.
4-3-3-1Do OEM (original equipment manufacturer) initialization.
4-3-3-2Initialize interrupt controller.
4-3-3-3Read in bootstrap code.
4-3-3-4Initialize all vectors.
4-3-4-1Boot the Flash program.
4-3-4-2Initialize the boot device.
4-3-4-3The boot code was read OK.
Two-tone sirenPOST done, prepare to boot the operating system.
Troubleshooting Tips:
  • RAM Problems: Common culprit – try reseating modules or testing one at a time.
  • CMOS Settings: Try clearing CMOS (the manual provides detailed steps). May fix odd behaviors.
  • Peripheral Conflicts: Temporarily remove expansion cards to test if issues disappear.

Important: Refer to your specific motherboard or computer manual for the most accurate codes for your system. Code variations exist between motherboard manufacturers using Phoenix BIOS.

For additional solutions, see our troubleshooting tips here.

IBM Desktop Beep Code Patterns

IBM desktop computers, especially older models, often use beep codes to signal startup problems. These codes can help you pinpoint potential hardware issues without the need for detailed error messages on the screen. Below is a table of common IBM Desktop Beep Code Patterns to aid in your troubleshooting.

Beep Code PatternMeaning
No BeepsNo power, power supply issues, or major system failure.
1 Short BeepSystem OK (normal boot).
2 Short BeepsPOST error (details may show on screen).
1 Long, 1 ShortMotherboard/system board issue.
1 Long, 2 ShortVideo adapter (display) problem.
1 Long, 3 ShortMemory (RAM) error.
Continuous BeepsPower supply problems.
Repeating BeepsPower supply, motherboard, or keyboard issues.
Troubleshooting Tips:
  • Pay close attention: Note the exact number of short and long beeps.
  • Consult your manual: Identify the precise meaning of the codes for your specific computer model.
  • Check basic connections: Start by ensuring your power supply is properly connected and functional.

Important: Beep code meanings can vary between specific IBM models. Always refer to your computer’s manual for the most accurate guide.

For additional solutions, see our troubleshooting tips here.

IBM ThinkPad Beep Code Patterns

IBM ThinkPad laptops utilize a distinct set of beep codes to alert you to potential hardware issues during startup. Learning to interpret these beeps can provide valuable clues for troubleshooting.

Beep Code PatternMeaning
No BeepsPower supply, system board, or possibly LCD issues.
1 Short BeepThe system is OK (normal boot).
2 Short BeepsPOST error (details might be displayed on screen).
1 Long, 2 Short BeepsSystem board issue.
1 Long, 3 Short BeepsMemory error.
3 Short, Pause, 3 Short, Pause, 3 ShortSystem board, memory, or video error.
Continuous BeepsOverheating or system board issue.
Troubleshooting Tips:
  • Note the Pattern: Be precise about the number of beeps and any pauses.
  • Use your Manual: Match the codes precisely to your ThinkPad’s model.
  • Focus on RAM: Memory problems are a common trigger for ThinkPad beep codes. Test with different RAM modules if possible.
  • Consider Overheating: Clean fans and vents; use your laptop on a hard surface for airflow.

Important: Consult your specific ThinkPad model’s documentation for the most accurate list of beep codes, as they may vary slightly across different models and generations.

For additional solutions, see our troubleshooting tips here.

Insyde Beep Code Patterns

Insyde BIOS is popular in modern laptops and some desktops. Let’s look at the specific beep codes it uses to signal potential hardware problems:

Beep Code PatternMeaning
2 ShortPOST Error (details might be displayed on screen).
5 Short, 1 LongProblem with the DMA page registers.
4 Short, 1 Long, 1 ShortThe circuit for refreshing RAM not working.
4 Short, 2 ShortBIOS ROM checksum failure.
3 Short, 1 Long, 2 ShortCMOS RAM test failure.
3 Short, 1 Long, 1 Short, 1 LongDMA controller failure.
3 Short, 2 Long, 1 ShortInterrupt controller failure.
3 Short, 3 LongKeyboard self-test issue.
2 Short, 1 Long, 3 ShortVideo card not found.
2 Short, 1 Long, 2 Short, 1 LongNo RAM installed or RAM not recognized.
Troubleshooting Tips:
  • Note the Specific Pattern: Distinguish between short and long beeps to find the matching code.
  • Recent Upgrade? Issues arising after a new hardware installation can point to compatibility problems.
  • Test Memory: Reseat your RAM or try booting with one module at a time to isolate issues.
Important Notes:
  • Check for Variations: Insyde may use code variations across different manufacturers. Consult your specific motherboard or laptop manual.
  • BIOS Updates: Sometimes a BIOS update can resolve odd beep code behavior.

For additional solutions, see our troubleshooting tips here.

Mylex Beep Code Patterns

Mylex, known for its RAID controllers, used a set of beep codes to diagnose startup issues. Here’s what those beeps mean:

Beep Code PatternMeaning
1 BeepNormal boot: The system passed self-test and is booting normally.
2 BeepsVideo adapter error.
3 BeepsKeyboard controller error.
4 BeepsKeyboard error (might be cable, keyboard itself, or controller).
5 and 6 BeepsProgrammable Interrupt Controller (PIC) error.
7 BeepsDMA page register error.
8, 9, and 10 BeepsRAM error (various causes).
11, 12, and 13 BeepsDMA Controller error.
14, 15, and 16 BeepsCMOS Issues (dead battery, checksum failures, etc.).
Troubleshooting Tips:
  • Video Errors: Reseat your video card, and test with a different card if possible.
  • Keyboard Issues: Test a different keyboard, and check cable connections.
  • Memory Errors: Reseat RAM, and test individual modules. Consider RAM replacement.
  • CMOS Problems: Replace the CMOS battery (usually a standard type). Some advanced motherboards may let you clear CMOS with a jumper (refer to your model’s manual).

Important: Mylex systems are likely specialized and potentially older. While these codes provide a starting point, further troubleshooting might require detailed knowledge of server components.

For additional solutions, see our troubleshooting tips here.

Compaq Beep Code Patterns

Encountering beeps with your vintage Compaq system? Here’s your guide to understanding those classic error codes:

Beep Code PatternMeaning
1 Long Neverending BeepMemory error.
1 Long, 1 Short BeepBIOS ROM checksum error.
1 Long, 2 Short BeepsVideo error.
1 Short BeepNo Error (the system is booting properly).
2 Short BeepsGeneral motherboard/POST error.
1 Short, 2 Long BeepsBad RAM.
7 Beeps (1L, 1S, 1L, 1S, Pause, 1L, 1S, 1S)AGP video card error.
Troubleshooting Tips:
  • Memory Issues: Reseat your RAM modules. Test with different RAM, if possible.
  • Video Problems: Ensure your video card is properly seated. If present, check any additional power connectors.
  • ROM Checksum Error: This potentially indicates issues with corrupted BIOS on your motherboard.
  • Recent Changes: Did the problem start after hardware modification? Try removing that change temporarily.
Important Notes:
  • Dated Systems: These codes primarily apply to older Compaq PCs.
  • Consult Your Manual: Always refer to your specific Compaq computer model’s manual for the most accurate and comprehensive list of beep codes.

For additional solutions, see our troubleshooting tips here.

Quadtel Beep Code Patters

Quadtel BIOS uses a simple set of beep codes to indicate errors. Below is a guide to help you understand the most common ones:

Beep Code PatternMeaning
1 Short BeepNormal Boot: The system is booting normally.
2 Short BeepsCMOS IC error: The CMOS RAM is faulty.
1 Long, 2 ShortVideo failure: The video adapter is faulty.
1 Long, 3 ShortPeripheral controller error.
Troubleshooting Tips:
  • CMOS Issues: Try clearing CMOS (refer to your motherboard manual for the exact method). If the issue persists, the CMOS battery or CMOS chip may need replacement.
  • Video Problems: Reseat the video card (remove and reinsert). If you have a dedicated graphics card, ensure additional power connectors are secure.
  • Other Peripherals: If you recently installed expansion cards or hardware, temporarily remove them to see if it resolves the beeps.

Important: This list might not be exhaustive. If you encounter different Quadtel beep patterns, double-check your motherboard manual as the most reliable source.

For additional solutions, see our troubleshooting tips here.

Macintosh Startup Tones

Unlike traditional BIOS beep codes, Apple’s Macintosh computers use distinctive startup sounds to communicate their status. These tones help troubleshoot without the need for detailed on-screen error messages.

Common Macintosh Startup Sounds:
  • Normal Startup Chime: The classic “bong” sound means your Mac passed its initial self-test and is booting normally.
  • Death Chimes: A jarring sound resembling a car crash or other discordant tones indicates a serious hardware problem, often related to RAM or other core components.
  • No Sound: This could signify issues with speakers, the power supply, or major motherboard faults.
Additional Notes:
  • Variations: Specific startup tones can differ across older and newer Mac models. Some Macs also incorporate startup tone variations to signal firmware issues.
  • Apple Resources: Check out Apple’s support site for information about startup sounds relevant to your macOS version: https://support.apple.com/
Troubleshooting Tips:
  • RAM Focus: Memory modules are a common culprit behind the “Death Chimes.” Reseat or swap RAM if possible.
  • Check Connections: Make sure internal and external speakers are working properly.
  • Reset PRAM/NVRAM: This can sometimes resolve sound-related issues (specific steps vary by model).
  • Professional Help: For issues beyond simple troubleshooting, seek assistance from an Apple technician.

Troubleshooting Tips

BIOS beep codes can be mysterious, but troubleshooting doesn’t have to be. Start with these basics:

  1. Carefully note the pattern: Is it short beeps, long beeps, repeating? This detail points you in the right direction.
  2. Consult your manual (or search online): Search for “[Motherboard Manufacturer] BIOS beep codes” to find a complete list.
  3. Common culprits:
    • RAM: Reseat RAM modules (remove and firmly reinsert) or try with a single stick.
    • Video Card: Ensure it’s seated properly and any power connectors are secure.
    • CPU: Check if the fan is spinning; more advanced users can reseat the CPU (use caution).
  4. Check connections: Make sure your monitor, keyboard, and mouse are properly plugged in.
  5. Recent changes? Did issues start after a hardware upgrade? Test by temporarily removing the new component.
  6. Reset BIOS: This can sometimes fix issues (BIOS menu or by removing the battery briefly – research the right method for your motherboard).
  7. No beeps? This could be more serious—suspect the power supply or processor itself.
  8. If in doubt, get help: A computer technician can pinpoint complex problems and advise on appropriate solutions.

Remember, BIOS beep codes provide a handy starting point for troubleshooting. By learning to interpret them, you can gain valuable insights into potential hardware problems and save yourself a lot of frustration!


BIOS beep codes offer valuable clues when your PC won’t boot. By understanding these patterns, you can gain a deeper understanding of your hardware and potentially troubleshoot basic errors yourself. With the right resources and a bit of investigation, those beeps won’t sound so cryptic anymore!

author avatar
Derick Payne
My name is Derick Payne. With a deep-seated passion for programming and an unwavering commitment to innovation, I've spent the past 23 years pushing the envelope of what's possible. As the founder of Rizonetech and Rizonesoft, I've had the unique opportunity to channel my love for technology into creating solutions that make a difference.

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