Computer BIOS Error Codes POST Beep Codes

The computer POST (power-on self-test) checks a computer’s internal hardware for compatibility and connection before starting the remainder of the boot process. If the computer passes the POST test, it starts and continue to boot. However, if the computer fails the POST test, the computer will generate a series of long and short beeps that tells the user the source of the problem.

AST Research BIOS

Long Beep Short Beep Descriptions
0 1 Low level processor verification test failed (POST 1)
0 2 Clearing keyboard controller buffers failed (POST 2)
0 3 Keyboard controller reset failed (POST 3)
0 4 Low level keyboard controller interface test (POST 4)
0 5 Reading data from keyboard controller failed (POST 5)
0 6 System board support chip initialization failed (POST 6)
0 7 Processor register read/write verify test failed (POST 7)
0 8 CMOS timer initialization failed (POST 8)
0 9 ROM BIOS checksum test failed (POST 9)
0 10 Initialize primary video (POST 10)
0 11 8254 timer channel 0 test failed (POST 11)
0 12 8254 timer channel 1 test failed (POST 12)
0 13 8254 timer channel 2 test failed (POST 13)
0 14 CMOS power-on and time test failed (POST 14)
0 15 CMOS shutdown byte test failed (POST 15)
1 0 DMA channel 0 test failed (POST 16)
1 1 DMA channel 1 test failed (POST 17)
1 2 DMA page register test failed (POST 18)
1 3 Keyboard controller interface test failed (POST 19)
1 4 Memory refresh toggle test failed (POST 20)
1 5 First 64 KB memory test failed (POST 21)
1 6 Setup interrupt vector table failed (POST 22)
1 7 Video initialization failed (POST 23)
1 8 Video memory test failed (POST 24)

AST Enhanced BIOS

Short Beep Long Beep Short Beep Descriptions
3 1 Flash loader failure
3 2 Failure in system board component
3 3 Failure in system board component
3 4 Memory failure
3 5 Video failure
0 6 Flash BIOS update error
2 x AST low level diagnostics

AST Phoenix BIOS

Beeps Descriptions
1-1-3 CMOS read/write failure
1-1-4 ROM BIOS checksum failure
1-2-1 Programmable interval timer failure
1-2-2 DMA initialization failure
1-2-3 DMA page register read/write failure
1-3-1 RAM refresh verification failure
1-3-3 First 64 KB RAM chip or data or data line failure
1-3-4 First 64 KB RAM odd/even logic failure
1-4-1 First 64 KB RAM address line failure
1-4-2 First 64 KB RAM parity failure
2-1-1 First 64 KB RAM failure bit 0
2-1-2 First 64 KB RAM failure bit 1
2-1-3 First 64 KB RAM failure bit 2
2-1-4 First 64 KB RAM failure bit 3
2-2-1 First 64 KB RAM failure bit 4
2-2-2 First 64 KB RAM failure bit 5
2-2-3 First 64 KB RAM failure bit 6
2-2-4 First 64 KB RAM failure bit 7
2-3-1 First 64 KB RAM failure bit 8
2-3-2 First 64 KB RAM failure bit 9
2-3-3 First 64 KB RAM failure bit A
2-3-4 First 64 KB RAM failure bit B
2-4-1 First 64 KB RAM failure bit C
2-4-2 First 64 KB RAM failure bit D
2-4-3 First 64 KB RAM failure bit E
2-4-4 First 64 KB RAM failure bit F
3-1-1 Slave DMA register failure
3-1-2 Master DMA register failure
3-1-3 Slave interrupt mask register failure
3-1-4 Slave interrupt mask failure
3-2-4 Keyboard controller test failure
3-3-4 Screen memory test failure
3-4-1 Screen initialization failure
3-4-2 Screen retrace test failure
3-4-3 Failure searching for video ROM
4-2-1 No timer tick
4-2-3 Gate-A20 failure
4-2-4 Unexpected interrupt in protected mode

WINBIOS

Beeps Error Message Description Resolution
1 Refresh Failure The memory refresh circuitry is faulty. Reseat the memory SIMMs. If the system still beeps, replace the memory.
2 Parity Error Parity error in the base memory (the first 64 KB block) of memory. Reseat the memory SIMMs. If the system still beeps, replace the memory.
3 Base 64 KB Memory Failure Memory failure in first 64 KB. Reseat the memory SIMMs. If the system still beeps, replace the memory.
4 Timer Not Operational A memory failure in the first 64 KB of memory, or Timer 1 is not functioning. The motherboard must be replaced.
5 Processor error 8042 – Gate A20 Failure The CPU generated an error. The motherboard must be replaced.
6 8042 – Gate A20 Failure Processor Exception Interrupt Error Cannot switch to protected mode. Try a different keyboard, or replace the keyboard fuse, if the keyboard has one.
7 Processor Exception Interrupt Error The CPU on the CPU Card generated an exception interrupt. The motherboard must be replaced.
8 Display Memory Read/Write Error The system video adapter is either missing or its memory is faulty. This is not a fatal error. There is a memory error on the video adapter. Replace the video adapter, or the RAM on the video adapter.
9 ROM Checksum Error The ROM checksum value does not match the value encoded in WINBIOS. The BIOS ROM chip is bad. The system probably needs a new BIOS ROM chip.
10 CMOS Shutdown Register Read/Write Error The shutdown register for CMOS RAM has failed. The motherboard must be replaced.
11 Cache memory bad – do not enable cache The cache memory test failed. Cache memory is disabled. Do not press Ctrl/Alt/Shift <+> to enable cache memory. The motherboard must be replaced.

AMI BIOS beep codes

Beep Code Descriptions
1 short DRAM refresh failure
2 short Parity circuit failure
3 short Base 64K RAM failure
4 short System timer failure
5 short Process failure
6 short Keyboard controller Gate A20 error
7 short Virtual mode exception error
8 short Display memory Read/Write test failure
9 short ROM BIOS checksum failure
10 short CMOS shutdown Read/Write error
11 short Cache Memory error
1 long, 3 short Conventional/Extended memory failure
1 long, 8 short Display/Retrace test failed
two-tone siren Low CPU Fan speed, Voltage Level issue

AWARD BIOS beep codes

Beep Code Description
1 long, 2 short Indicates a video error has occurred and the BIOS cannot initialize the video screen to display any additional information
1 long, 3 short Video card not detected (reseat video card) or bad video card
Beeps repeating endlessly RAM problem.
Repeated high frequency beeps while PC is running Overheating processor (CPU)
Repeated beeps alternating high & low frequency Issue with the processor (CPU), possibly damaged

Dell beep codes

Beep Code Description
1 beep BIOS ROM corruption or failure
2 beeps Memory (RAM) not detected
3 beeps Motherboard failure
4 beeps Memory (RAM) failure
5 beeps CMOS Battery failure
6 beeps Video card failure
7 beeps Bad processor (CPU)

IBM BIOS beep codes

Beep Code Description
No Beeps No Power, Loose Card, or Short.
1 Short Beep Normal POST, computer is ok.
2 Short Beep POST error, review screen for error code.
Continuous Beep No Power, Loose Card, or Short.
Repeating Short Beep No Power, Loose Card, or Short.
1 Long and 1 Short Beep Motherboard issue.
1 Long and 2 Short Beeps Video (Mono/CGA Display Circuitry) issue.
1 Long and 3 Short Beeps. Video (EGA) Display Circuitry.
3 Long Beeps Keyboard or Keyboard card error.
1 Beep, Blank or Incorrect Display Video Display Circuitry.

IBM POST Diagnostic Code Descriptions

Diagnostic Code Descriptions
100 – 199 System Board
200 – 299 Memory
300 – 399 Keyboard
400 – 499 Monochrome Display
500 – 599 Color/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 Color/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

Macintosh startup tones

Tones Error
Error Tone. (two sets of different tones) Problem with logic board or SCSI bus.
Startup tone, drive spins, no video Problem with video controller.
Powers on, no tone. Logic board problem.
High Tone, four higher tones. Problem with SIMM.

Phoenix BIOS beep codes

Beep codes for Phoenix BIOS Q3.07 OR 4.X

Beep Code Description and what to check
1-1-1-1 Unconfirmed beep code. Reseat RAM chips or replace RAM chips as possible solution
1-1-1-3 Verify Real Mode.
1-1-2-1 Get CPU Type.
1-1-2-3 Initialize system hardware.
1-1-3-1 Initialize chipset registers with initial POST values.
1-1-3-2 Set in POST flag.
1-1-3-3 Initialize CPU registers.
1-1-4-1 Initialize cache to initial POST values.
1-1-4-3 Initialize I/O.
1-2-1-1 Initialize Power Management.
1-2-1-2 Load alternate registers with initial POST values.
1-2-1-3 Jump to UserPatch0.
1-2-2-1 Initialize keyboard controller.
1-2-2-3 BIOS ROM checksum.
1-2-3-1 8254 timer initialization.
1-2-3-3 8237 DMA controller initialization.
1-2-4-1 Reset Programmable Interrupt Controller.
1-3-1-1 Test DRAM refresh.
1-3-1-3 Test 8742 Keyboard Controller.
1-3-2-1 Set ES segment to register to 4 GB.
1-3-3-1 28 Autosize DRAM.
1-3-3-3 Clear 512K base RAM.
1-3-4-1 Test 512 base address lines.
1-3-4-3 Test 512K base memory.
1-4-1-3 Test CPU bus-clock frequency.
1-4-2-4 Reinitialize the chipset.
1-4-3-1 Shadow system BIOS ROM.
1-4-3-2 Reinitialize the cache.
1-4-3-3 Autosize cache.
1-4-4-1 Configure advanced chipset registers.
1-4-4-2 Load alternate registers with CMOS values.
2-1-1-1 Set Initial CPU speed.
2-1-1-3 Initialize interrupt vectors.
2-1-2-1 Initialize BIOS interrupts.
2-1-2-3 Check ROM copyright notice.
2-1-2-4 Initialize manager for PCI Options ROMs.
2-1-3-1 Check video configuration against CMOS.
2-1-3-2 Initialize PCI bus and devices.
2-1-3-3 Initialize all video adapters in system.
2-1-4-1 Shadow video BIOS ROM.
2-1-4-3 Display copyright notice.
2-2-1-1 Display CPU Type and speed.
2-2-1-3 Test keyboard.
2-2-2-1 Set key click if enabled.
2-2-2-3 56 Enable keyboard.
2-2-3-1 Test for unexpected interrupts.
2-2-3-3 Display prompt Press F2 to enter SETUP.
2-2-4-1 Test RAM between 512 and 640k.
2-3-1-1 Test expanded memory.
2-3-1-3 Test extended memory address lines.
2-3-2-1 Jump to UserPatch1.
2-3-2-3 Configure advanced cache registers.
2-3-3-1 Enable external and CPU caches.
2-3-3-3 Display external cache size.
2-3-4-1 Display shadow message.
2-3-4-3 Display non-disposable segments.
2-4-1-1 Display error messages.
2-4-1-3 Check for configuration errors.
2-4-2-1 Test real-time clock.
2-4-2-3 Check for keyboard errors
2-4-4-1 Set up hardware interrupts vectors.
2-4-4-3 Test coprocessor if present.
3-1-1-1 Disable onboard I/O ports.
3-1-1-3 Detect and install external RS232 ports.
3-1-2-1 Detect and install external parallel ports.
3-1-2-3 Re-initialize onboard I/O ports.
3-1-3-1 Initialize BIOS Data Area.
3-1-3-3 Initialize Extended BIOS Data Area.
3-1-4-1 Initialize floppy controller.
3-2-1-1 Initialize hard disk controller.
3-2-1-2 Initialize local bus hard disk controller.
3-2-1-3 Jump to UserPatch2.
3-2-2-1 Disable A20 address line.
3-2-2-3 Clear huge ES segment register.
3-2-3-1 Search for option ROMs.
3-2-3-3 Shadow option ROMs.
3-2-4-1 Set up Power Management.
3-2-4-3 Enable hardware interrupts.
3-3-1-1 Set time of day.
3-3-1-3 Check key lock.
3-3-3-1 Erase F2 prompt.
3-3-3-3 Scan for F2 key stroke.
3-3-4-1 Enter SETUP.
3-3-4-3 Clear in POST flag.
3-4-1-1 Check for errors
3-4-1-3 POST done – prepare to boot operating system.
3-4-2-1 One beep.
3-4-2-3 Check password (optional).
3-4-3-1 Clear global descriptor table.
3-4-4-1 Clear parity checkers.
3-4-4-3 Clear screen (optional).
3-4-4-4 Check virus and backup reminders.
4-1-1-1 Try to boot with INT 19.
4-2-1-1 Interrupt handler error.
4-2-1-3 Unknown interrupt error.
4-2-2-1 Pending interrupt error.
4-2-2-3 Initialize option ROM error.
4-2-3-1 Shutdown error.
4-2-3-3 Extended Block Move.
4-2-4-1 Shutdown 10 error.
4-3-1-3 Initialize the chipset.
4-3-1-4 Initialize refresh counter.
4-3-2-1 Check for Forced Flash.
4-3-2-2 Check HW status of ROM.
4-3-2-3 BIOS ROM is OK.
4-3-2-4 Do a complete RAM test.
4-3-3-1 Do OEM initialization.
4-3-3-2 Initialize interrupt controller.
4-3-3-3 Read in bootstrap code.
4-3-3-4 Initialize all vectors.
4-3-4-1 Boot the Flash program.
4-3-4-2 Initialize the boot device.
4-3-4-3 Boot code was read OK.
two-tone siren Low CPU Fan speed, Voltage Level issue

Computer BIOS Error Codes POST Beep Codes