IBM POST Error Codes

Code Description
1 short beep System is OK
2 short beeps POST Error – error code shown on screen No beep Power supply or system board problem Continuous beep Power supply, system board, or keyboard problem Repeating short beeps Power supply or system board problem
1 long, 1 short beep System board problem
1 long, 2 short beeps Display adapter problem (MDA, CGA)
1 long, 3 short beeps Display adapter problem (EGA)
3 long beeps 3270 keyboard card

IBM POST Diagnostic Code Descriptions
Code Description
100 – 199 System Board
200 – 299 Memory
300 – 399 Keyboard
400 – 499 Monochrome Display
500 – 599 Colour/Graphics Display
600 – 699 Floppy-disk drive and/or Adapter
700 – 799 Math Coprocessor
900 – 999 Parallel Printer Port
1000 – 1099 Alternate Printer Adapter
1100 – 1299 Asynchronous Communication Device, Adapter, or Port
1300 – 1399 Game Port
1400 – 1499 Colour/Graphics Printer
1500 – 1599 Synchronous Communication Device, Adapter, or Port
1700 – 1799 Hard Drive and/or Adapter
1800 – 1899 Expansion Unit (XT)
2000 – 2199 Bisynchronous Communication Adapter
2400 – 2599 EGA system-board Video (MCA)
3000 – 3199 LAN Adapter
4800 – 4999 Internal Modem
7000 – 7099 Phoenix BIOS Chips
7300 – 7399 3.5″ Disk Drive
8900 – 8999 MIDI Adapter
11200 – 11299 SCSI Adapter
21000 – 21099 SCSI Fixed Disk and Controller
21500 – 21599 SCSI CD-ROM System

AMI BIOS Beep Codes
Code Description

1 Short Beep System OK
2 Short Beeps Parity error in the first 64 KB of memory
3 Short Beeps Memory failure in the first 64 KB
4 Short Beeps Memory failure in the first 64 KB Operational of memory
or Timer 1 on the motherboard is not functioning
5 Short Beeps The CPU on the motherboard generated an error
6 Short Beeps The keyboard controller may be bad. The BIOS cannot switch to protected mode
7 Short Beeps The CPU generated an exception interrupt
8 Short Beeps The system video adapter is either missing, or its memory is faulty
9 Short Beeps The ROM checksum value does not match the value encoded in the BIOS
10 Short Beeps The shutdown register for CMOS RAM failed
11 Short Beeps The external cache is faulty
1 Long, 3 Short Beeps Memory Problems
1 Long, 8 Short Beeps Video Card Problems

Phoenix BIOS Beep Codes
Note – Phoenix BIOS emits three sets of beeps, separated by a brief pause.

Code Description
1-1-3 CMOS read/write failure
1-1-4 ROM BIOS checksum error
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 failure
1-3-3 First 64k RAM chip or data line failure
1-3-4 First 64k RAM odd/even logic failure
1-4-1 Address line failure first 64k RAM
1-4-2 Parity failure first 64k RAM
2-_-_ Faulty Memory
3-1-_ Faulty Motherboard
3-2-4 Keyboard controller Test failure
3-3-4 Screen initialisation failure
3-4-1 Screen retrace test failure
3-4-2 Search for video ROM in progress
4-2-1 Timer tick interrupt in progress or failure
4-2-2 Shutdown test in progress or failure
4-2-3 Gate A20 failure
4-2-4 Unexpected interrupt in protected mode

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