POST Beep Code Reference
Look up what a POST beep pattern means, and what to try first.
What you provide
Result
11 codes listed for AMI
Beep codes point at a subsystem, not at a component. A memory code means the board could not talk to memory, which is caused by a bad stick, a dirty contact, a slot that is not making connection, or a processor with a bent pin in the memory controller. Reseating is free and fixes a large share of them, so it comes first. These patterns also vary by board and by firmware revision, so treat the table as a starting point and check the manual for the specific board where you can.
1 Memory refresh failure 2 Memory parity error 3 Base memory failure in the first 64 KB 4 System timer failure 5 Processor failure 6 Keyboard controller failure 7 Processor exception error 8 Display memory failure 9 BIOS checksum error 1 long, 3 short Memory test failure 1 long, 8 short Display test failure
- 1Reseat the memory. If it repeats, test one stick at a time in the first slot.
- Memory refresh failure
- 2Reseat the memory, then swap sticks to find which one fails.
- Memory parity error
- 3Almost always the memory itself. Test each stick individually.
- Base memory failure in the first 64 KB
- 4A board-level fault. Clear CMOS first, but expect to replace the board.
- System timer failure
- 5Reseat the cooler and check the CPU power connector before condemning the processor.
- Processor failure
- 6Unplug all USB devices and retry with nothing attached.
- Keyboard controller failure
- 7Reseat the processor and inspect the socket pins under a light.
- Processor exception error
- 8Reseat the graphics card, or try a different one.
- Display memory failure
- 9Clear CMOS and replace the coin cell. If it persists, the BIOS chip is failing.
- BIOS checksum error
- 1 long, 3 shortReseat and test memory one stick at a time.
- Memory test failure
- 1 long, 8 shortReseat the graphics card and check the monitor cable.
- Display test failure
What this cannot tell you
- A reference table, not a diagnosis. Nothing here reads your machine, and no web page can hear your motherboard.
- Beep patterns vary by board and by firmware revision even within one BIOS vendor, and they may change between revisions. Verify with vendor documentation for your specific board, since a code that means memory on one board can mean something else on another.
Take this with you
How this calculation works
Pick the BIOS vendor and search by pattern or by symptom. Each entry gives the subsystem the code points at, the first thing worth trying, and how confident you should be in that reading. The confidence column matters because these codes are not equally reliable: a memory code is a strong signal and a timer code is often the board reporting that something else upstream failed.
What the results mean
- Meaning
- The subsystem the firmware could not initialise. It names where the failure was detected, which is not always where the fault is.
- What to try
- The cheapest test that meaningfully narrows it down. Reseating costs nothing and resolves a surprising share of these codes.
- Confidence
- How reliably the code identifies the actual fault. Memory and video codes are dependable; timer and chipset codes frequently point at something else.
Common problems and fixes
- No beeps at all, just no display
- Many modern boards have no speaker fitted, so there is nothing to beep with. Check for a small two-pin speaker header on the board, or look for diagnostic LEDs, which most boards from the last decade use instead. Boards with a code display show a two-digit hexadecimal code that is far more precise than any beep.
- The pattern does not match anything in the list
- Count again with the machine cold, since the first pattern after power-on is the reliable one and a repeating pattern is easy to miscount mid-sequence. Then check the board manual, because vendors customise these codes and a board maker using AMI firmware may not use the standard AMI patterns.
Frequently asked questions
What is a POST beep code?
Before anything can be shown on screen, the firmware tests the parts it needs to display something at all. If one of those fails, it has no way to tell you except through the speaker, so it beeps a pattern. That is why beep codes only exist for early failures, and why a machine that reaches the operating system never beeps.
One short beep at startup means a problem?
No, the opposite. A single short beep on most systems means every power-on test passed, which is why an older machine that used to beep once and now does not is worth a second look.
Should I replace a part based on a beep code?
Reseat before replacing, always. A large share of memory and video codes are contact problems rather than dead components, and reseating costs nothing. If it repeats after reseating, test with one component at a time to identify which is failing rather than buying a replacement for the whole subsystem.
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