7.01 What do the POST beeps mean?
Description
This item is from the PC Hardware FAQ, by Willie Lim and Ralph Valentino with numerous contributions by others. (v1.25).
7.01 What do the POST beeps mean?
This section contains information on the following:
IBM AMI Phoenix DTK/ERSO XT BIOS MR BIOS Mylex 386 System BIOS Quadtel AT Compatible BIOS
[From: Shaun Burnett (burnesa@cat.com)] POST (Power-On Self Test) beeps signal something is wrong with your system. The meaning of these beeps is BIOS dependent. Below are the audio codes for IBM, AMI, and Phoenix BIOS's.
IBM
Beep(s) Errant device No beep Power supply, system board 1 short beep System OK 2 short beeps POST Error displayed on monitor Repeating short beeps Power supply, system board 3 long beeps 3270 keyboard card 1 long, 1 short beeps System board 1 long, 2 short beeps Display adapter (MDA, CGA) 1 long, 3 short beeps EGA Continuous beep Power supply, system board
AMI
Beep(s) Failure 1 short DRAM refresh 2 short Parity circuit 3 short Base 64K RAM 4 short System timer 5 short Processor 6 short Keyboard controller Gate A20 error 7 short Virtual mode exception error 8 short Display memory R/W test 9 short ROM BIOS checksum 1 long, 3 short Non-fatal--Conventional/extended memory 1 long, 8 short Non-fatal--Display/retrace test
PHOENIX
Beep Fatal Failures* Beep code Non-Fatal Failures* code
1-1-3 CMOS write/read (or real- 4-2-1 Timer tick interrupt test
time clock read/write) (or in progress)
1-1-4 ROM BIOS checksum 4-2-2 Shutdown test (or in progress)
1-2-1 Programmable interval timer 4-2-3 Gate A20 failure
1-2-2 DMA initialization 4-2-4 Unexpected interrupt in
protected mode
1-2-3 DMA page register write/read 4-3-1 RAM test in progress or
address failure > FFFFh
1-2-4 SRAM test and configuration 4-3-3 Interval timer Channel 2
(or test)
1-3-1 RAM refresh verification 4-3-4 Time-of-day clock (or test)
1-3-3 1st 64kb RAM chip or data 4-4-1 Serial port (or test)
line failure, multibit
1-3-4 First 64K RAM odd/even logic 4-4-2 Parallel port (or test)
1-4-1 Address line failure first 4-4-3 Math coprocessor (or test)
64K RAM
1-4-2 Parity failure first low 1-1-2 System-board select
64K RAM
2-1-1 Bit 0 first 64K RAM low 1-1-3 Extended CMOS RAM
2-1-2 Bit 1 first 64K RAM
2-1-3 Bit 2 first 64K RAM
2-1-4 Bit 3 first 64K RAM
2-2-1 Bit 4 first 64K RAM
2-2-2 Bit 5 first 64K RAM
2-2-3 Bit 6 first 64K RAM
2-2-4 Bit 7 first 64K RAM
2-3-1 Bit 8 first 64K RAM
2-3-2 Bit 9 first 64K RAM
2-3-3 Bit 10 first 64K RAM
2-3-4 Bit 11 first 64K RAM
2-4-1 Bit 12 first 64K RAM
2-4-2 Bit 13 first 64K RAM
2-4-3 Bit 14 first 64K RAM
2-4-4 Bit 15 first 64K RAM
3-1-1 Slave DMA register
3-1-2 Master DMA register
3-1-3 Master interrupt mask
register failure
3-1-4 Slave interrupt mask
register failure
3-2-4 Keyboard controller test
failure
3-3-4 Screen initialization
3-4-1 Screen retrace
3-4-2 Search for video ROM in
progress (not failure)
* Unless otherwise noted.
[From: Will Spencer (will@gnu.ai.mit.edu)]
DTK/ERSO XT BIOS
1 short - Begin POST and End POST 1 long, 1 short - Floppy Disk Drive or Controller Failure Continuous short - Parity Error in First 64K RAM Continuous tone - First 64K RAM failure 1 long - Keyboard Failed or Locked, Interrupt or other system board error long short, long short, long short - Video Initialization Failure, or Invalid Video Switch Setting
MR BIOS
:POST Code 1A Beep Codes low high, low high low high high - Real Time Clock is Not Updating :POST Code 03 Beep Codes low high, low low low - ROM BIOS Checksum Test :POST Code 04 Beep Codes low high, high low low - Page Register Test (Ports 81-8F) :POST Code 05 Beep Codes low high, low high low - 8042 Keyboard Controller Selftest :POST Code 07 Beep Codes low high, high high low - Memory Refresh Circuit Test :POST Code 08 Beep Codes low high, low low high - Master (16bit) DMA Controller Failure low high, high low high - Slave (8 bit) DMA Controller Failure :Post Code 0A Beep Codes low high, low low low low - Memory Bank 0 Pattern Test Failure low high, high low low low - Memory Bank 0 Parity Circuitry Failure low high, low high low low - Memory Bank 0 Parity Error low high, high high low low - Memory Bank 0 Data Bus Failure low high, low low high low - Memory Bank 0 Address Bus Failure low high, high low high low - Memory Bank 0 Block Access Read Failure low high, low high high low - Memory Bank 0 Block Access Read/Write Failure :POST Code 0B Beep Codes low high, high high high low - Master 8259 (Port 21 ) Failure low high, low low low high - Slave 8259 (Port A1) Failure :POST Code 0C Beep Codes low high, high low low high - Master 8259 (Port 20) Interrupt Address Error low high, low high low high - Slave 8259 (Port A0) Interrupt Address Error low high, high high low low - 8259 (Port 20/A0) Interrupt Address Error low high, low low high high - Master 8259 (Port 20) Stuck Intercept Error low high, high low high high - Slave 8259 (Port A0) Stuck Intercept Error low high, low high high high - System Timer 8254 CH0/IRQ0 Interrupt Failure :POST Code 0D Beep Codes low high, high high high high - 8254 Channel 0 Test and Initialization :POST Code 0E Beep Codes low high, low low low low high - 8254 Channel-2 (Speaker) Failure low high, high low low low high - 8254 OUT2 (Speaker Detect) Failure :POST Code 0F Beep Codes low high, low high low low high - CMOS RAM Read/Write Test Failure low high, high high low low high - RTC Periodic Interrupt / IRQ8 Failure :POST Code 10 Beep Codes low high, low low high low high - Video Initialization and (Cold-Boot) Signon Message :POST Code 12 Beep Codes low high, high low high low high - Keyboard Controller Failure :POST Code 17 Beep Codes low high, low low low high high - A20 Test Failure Due to 8042 Timeout low high, high low low high high - A20 Gate Stuck in Disabled State :POST Code 19 Beep Codes low high, low high high low high - Memory Parity Error low high, high high high low high - IO Channel Error
Mylex 386 System BIOS
long - Begin POST Beep Code 2 long - Video Card Bad or No Video Card long, short, long - Keyboard Controller Error long, 2 short, long - Keyboard Error long, 3 short, long - Programmable Interrupt Controller (8259-1) Error long, 4 short, long - Programmable Interrupt Controller (8259-1) Error long, 5 short, long - DMA Page Register Error long, 6 short, long - RAM Refresh Error long, 7 short, long - RAM Data Test Error long, 8 short, long - RAM Parity Error long, 9 short, long - DMA Controller 1 Error long, 10 short, long - CMOS RAM Failure long, 11 short, long - DMA Controller 2 Error long, 12 short, long - CMOS RAM Battery Failure long, 13 short, long - CMOS Checksum Failed long, 14 short, long - BIOS ROM Checksum Failed several long beeps - Multiple failures
Quadtel AT Compatible BIOS
3 short - Any Failure
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