BIOS Beep Codes: How to Identify PC Startup Errors

Beeping before Windows loads usually means the computer failed part of its power-on self-test (POST). The pattern can point to memory, graphics, CPU, keyboard-controller, or motherboard trouble, but it is not universal: the same number of beeps can mean different things on different firmware and motherboard models.

Computer beeps, Computer error lookup table based on BIOS and CMOS beep sounds. Picture 1

Before using a beep-code table

Record the pattern exactly. Note whether the tones are short or long, whether they repeat, and whether there are pauses between groups.
Identify the motherboard or PC model. A prebuilt desktop or laptop may use a manufacturer-specific code instead of a generic AMI or Phoenix pattern.
Check the manual first. The support page for the exact PC or motherboard is the best authority for its codes. You can also check the BIOS version when the computer can still reach setup or Windows.
Disconnect power before reseating hardware. Shut down, unplug the computer, and follow antistatic precautions. Do not open a device that is under warranty if doing so could affect service coverage.

A single brief beep can indicate a successful POST on some older systems, while many newer computers boot silently. No beep is not proof that the motherboard is healthy; some systems have no internal speaker.

Common legacy AMI beep codes

The following table is a troubleshooting starting point for older AMI BIOS systems. Confirm the meaning in the documentation for your motherboard before buying or replacing a part.

Computer beeps, Computer error lookup table based on BIOS and CMOS beep sounds. Picture 2

Pattern	Likely area to check	Useful first step
1 short beep	POST completed on systems that use a success beep	Check the display if the computer still does not start normally.
2 or 3 short beeps	Base-memory or parity-related error	Power off, reseat the RAM, and test one compatible module at a time.
4 short beeps	System timer or motherboard-related error	Load appropriate firmware defaults and check the board documentation.
5 short beeps	Processor-related error	Check CPU power connections and cooling; avoid removing the processor unless you are experienced.
6 short beeps	Keyboard controller or gate A20 error	Disconnect unnecessary USB devices and try a known-good keyboard.
7 short beeps	Processor exception or motherboard error	Check the manual and inspect CPU power, cooling, and socket installation.
8 short beeps	Display-memory or graphics error	Reseat the graphics card and its power cables, or test integrated graphics if available.
9 short beeps	Firmware ROM checksum error	Use only the model-specific recovery or update procedure supplied by the manufacturer.
10 short beeps	CMOS shutdown-register error	Load firmware defaults; if settings or time are repeatedly lost, inspect the CMOS battery.
11 short beeps	Cache-memory error	Confirm the code in the manual; professional board-level diagnosis may be required.
1 long, 3 short	Memory-related error on some systems	Reseat and test the RAM.
1 long, 8 short	Video test or display-related error on some systems	Check the monitor connection and reseat the graphics card.

Common legacy Phoenix BIOS patterns

Phoenix codes are often expressed as groups separated by pauses. For example, 1-1-3 means one beep, a pause, one beep, a pause, then three beeps. The patterns below summarize the legacy meanings retained from the original reference; a motherboard-specific manual takes priority.

Computer beeps, Computer error lookup table based on BIOS and CMOS beep sounds. Picture 3

Pattern	Likely area to check
1-1-2, 1-2-2, 1-2-3, 1-3-1, 1-3-3, 1-3-4, or 1-4-1	Motherboard, memory-controller, or early POST failure
1-1-3	CMOS configuration read/write problem
1-1-4	Firmware ROM checksum problem
1-2-1	Programmable interval timer problem
1-4-2 or a pattern beginning 2-x-x	Memory problem
3-1-x	Chipset or motherboard problem
3-2-4	Keyboard-controller problem
3-3-4 or 3-4-x	Graphics adapter or video-memory problem
4-2-2 or 4-2-3	Keyboard or motherboard problem
4-2-4	Add-in card or connected-device problem
4-3-1, 4-3-2, or 4-3-3	Motherboard or timer-related problem
4-3-4	Real-time clock problem
4-4-1 or 4-4-2	Legacy serial or parallel port problem
4-4-3	Math coprocessor or CPU-related problem

A safe troubleshooting order

Turn the computer off and unplug it. Disconnect nonessential USB devices, external drives, and recently added accessories.
Check the monitor input, display cable, power leads, and motherboard diagnostic LEDs or code display, if present.
Undo the most recent hardware change. Reseat accessible RAM and expansion cards, then test with the minimum hardware needed to reach POST.
If there are multiple RAM modules, test one module at a time in the slot recommended by the motherboard manual. A successful boot helps isolate a module or slot, but compatibility can also be a factor.
If the clock and firmware settings reset after power is removed, follow a careful CMOS battery replacement guide. The battery does not power the BIOS itself; it helps retain the real-time clock and firmware settings while the PC is unplugged.
Only update firmware when the manufacturer specifically recommends it for the symptom and you have the exact file for the model. An interrupted or incorrect update can prevent the computer from booting. See the precautions in this safe BIOS update guide.

When to stop troubleshooting

Stop and seek qualified repair help if you smell burning, see liquid damage, find a swollen component, or are not comfortable working around internal hardware. Persistent CPU, firmware-ROM, or motherboard codes also deserve model-specific diagnosis before parts are replaced. Beep codes narrow the search; they do not prove that the named component has failed.

Before using a beep-code table

Common legacy AMI beep codes

Common legacy Phoenix BIOS patterns

A safe troubleshooting order

When to stop troubleshooting

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