PC (Personal Computer) BIOS POST Beep Codes
When your computer starts, you normally hear a rather cheerful beep that signals the beginning of great computing events to come. This cheerful (also referred to as long) beep is part of your computer’s start-up diagnostic routine, and signals a successful hardware and memory check. This process is known as the POST (Power On Self Test), and can be helpful for identifying problems with your computer system before you load your operating system.
When problems are detected, typically you will receive a series of short beeps to help you troubleshoot your computers potential problems.
The beeps codes are specific to the manufacturers BIOS. Here is a list of common codes, you may find useful.
AMI BIOS
| Number |
Duration of Beeps |
|
|
| 1 short |
DRAM refresh failure (Problem with memory) |
| 2 short |
Parity circuit failure |
| 3 short |
Base 64K RAM failure |
| 4 short |
System Timer failure |
| 5 short |
Processor failure |
| 6 short |
Keyboard Controller / Gate A20 failure |
| 7 short |
Virtual Mode Exception error |
| 8 short |
Display Memory Read/Write failure (video card fault) |
| 9 short |
ROM BIOS Checksum error (BIOS chip fault) |
| 10 short |
CMOS Shutdown Read/Write error |
| 11 short |
Cache memory |
| 1 long |
Passed (no errors) |
| 1 long/2 short |
Video failure |
| 1 long/3 short |
Base / Extended Memory failure |
| 1 long/8 short |
Display / Retrace Test failure |
Award BIOS
| Number |
Duration of Beeps |
|
|
| 1 short |
Passed (no errors) |
| 2 short |
Any non-fatal error |
| 1 long/2 short |
Video failure |
| 1 long/3 short |
Keyboard Controller failure (applies to 286/386/486) |
IBM BIOS
| Number |
Duration of Beeps |
|
|
| none |
Power Supply or System Board failure (possible short) |
| 1 short |
Passed (no errors) |
| 1 short |
(blank screen) Video error (check cable) |
| 1 short |
(no boot) Floppy Drive error |
| 2 short |
Configuration Error (displayed on screen) |
| repeated short |
Power Supply or System Board failure |
| continuous |
Power Supply or System Board/Keyboard stuck |
| 1 long/1 short |
System Board failure |
| 1 long/2 short |
Video (Mono/CGA) failure (check cable) |
| 1 long/3 short |
Video (EGA) failure (check cable) |
| 3 long |
Keyboard Card error |
Phoenix BIOS
| Number |
Duration of Beeps |
|
|
| 1/1/3 |
CMOS Read/Write |
| 1/1/4 |
ROM BIOS Checksum failure |
| 1/2/1 |
Programmable Interval Timer failure |
| 1/2/2 |
DMA Initialisation failure |
| 1/2/3 |
DMA Page Register Read/Write failure |
| 1/3/1 |
RAM Refresh Verification error |
| 1/3/3 |
First 64K RAM Chip/Data Line failure |
| 1/3/4 |
First 64K RAM Odd/Even Logic |
| 1/4/1 |
First 64K RAM: Address Line |
| 1/4/2 |
First 64K RAM: Parity failure |
| 1/4/3 |
Fail-Safe Timer Feature (EISA only) |
| 1/4/4 |
Software NMI Port failure (EISA only) |
| 4/2/4 |
Unexpected Interrupt in Protected Mode |
| 2/followed by various combinations |
|
First 64K RAM Chip/Data Line failure (combinations indicate which bit) |
| 3/1/1 |
Slave DMA Register failure |
| 3/1/2 |
Master DMA Register failure |
| 3/1/3 |
Master Interrupt Mask Register failure |
| 3/1/4 |
Slave Interrupt Mask Register failure |
| 3/2/4 |
Keyboard Controller failure |
| 3/3/4 |
Display Memory failure |
| 3/4/1 |
Display Retrace failure |
| 3/4/2 |
Video ROM search proceeding |
| 4/2/1 |
Timer Tick failure |
| 4/2/2 |
Shutdown failure |
| 4/2/3 |
Gate A20 failure |
| 4/3/1 |
RAM test above 64K failure |
| 4/3/2/3 |
Programmable Interval Timer, Channel 2 failure |
| 4/3/4 |
Realtime Clock failure |
| 4/4/1 |
Serial Port error |
| 4/4/2 |
Parallel Port error |
| 4/4/3 |
Math Co-processor failure |
| (tone) 1/1/2 |
System Board Select |
| (tone) 1/1/3 |
Extender CMOS RAM |