Error message when loading bios. Boot block checkpoints. AMI BIOS Error Signals.

Since you are here, it means that you are interested in BIOS error codes, or just decided to look in and find out what it is? In general, the thing is, about two weeks ago, when I turned on the computer, the BIOS “wrongly” squealed, I fixed my problem very quickly and slowly began to collect information about BIOSes, or rather about error codes, and today I am laying out tables with the BIOS version for you , the number of sounds, what this sound or code means and, in some cases, how to fix this problem.

How to find out the BIOS version?
It's simple, open context menu"Run" (Win + R), we type:

msinfo32

and click "OK".
A window will open...

Now in the "System Information" tab in the right window, below will be "BIOS Version".
Now everyone look at the table, look for your version, find the BIOS error code and see what it means, in some cases I also posted how to get rid of errors.

And so, here BIOS sounds and their designations.

Award BIOS Signals:

Number of signals	Designation	Solution
1 short	Successful POST (no errors found) and you can continue to work safely	-
2 short	Not significant errors	Check if the cables are tight hard drive and motherboard
3 long		Check the quality of the connection between the mouse and keyboard with the "mother"
continuous signal	Faulty power supply	... (here I think it's clear)
No signals	Power supply not connected to the motherboard or defective
1 long + 1 short	RAM errors	Take out the modules random access memory, blow off/wipe dust paste tightly
1 long + 2 short	Problems with the video adapter	Same as RAM
1 long + 3 short	Keyboard initialization errors	Check the reliability of the connection
1 long + 9 short	Error while reading data from ROM	The BIOS may not be suitable for your configuration.
Long repeating	Incorrect installation of memory modules	Perhaps the modules are not inserted tightly, or again they do not fit your hardware
Short recurring	Problems with the power supply	It may need to be replaced, but first try to clean it from dust)

AMI BIOS Signals:

Number of signals	Designation	Solution
1 short	No errors found	-
2 short		Check memory module installation
3 short	Error during main memory operation (first 64 KB)	see above
4 short	Faulty system timer
5 short	Faulty CPU
6 short	Faulty keyboard controller
7 short
8 short	Problems with the video adapter
9 short
10 short	Unable to write to CMOS memory
11 short	Faulty external cache
1 long + 2 short	Faulty video adapter
1 long + 3 short	Faulty video adapter
1 long + 8 short	Problems with the video adapter or the monitor is not connected

IBM BIOS Signals:

Number of signals	Designation	Solution
1 short	No errors found
1 long + 1 short	out of order motherboard
1 signal + blank screen	Faulty video system
1 long + 2 short	Faulty video system (Mono/CGA)
1 long + 3 short	Faulty video system (EGA/VGA)
2 short	Faulty video system (no monitor connected)
3 long	Faulty motherboard (keyboard controller error)
No signal	Faulty power supply or speakers
continuous signal	Faulty power supply
Repetitive short beeps	Faulty power supply

Compaq BIOS Signals:

Number of signals	Designation	Solution
1 short	No errors found	-
1 long + 1 short	Checksum error CMOS memory BIOS. Possibly dead ROM battery	Flash the BIOS or restore using the motherboard
2 short	Unknown error
1 long + 2 short	Video system error	Check that the video adapter is installed correctly, the video card may need to be replaced
7 signals (1d-1k-1d-1k-pause-1d-1k-1k)	Faulty AGP video card	see above
1 continuous beep	RAM error	Check if the memory is installed correctly. Check contacts. Replace memory modules.
1 short, 2 long	RAM error	see above

From the Phoenix BIOS:
Here, unlike other BIOS, interleaved signals.

Number of signals	Designation	Solution
1-1-3	Write/read error CMOS data
1-1-4	BIOS chip checksum error
1-2-1	Faulty motherboard
1-2-2	DMA controller initialization error
1-2-3	Error when trying to read/write to one of the DMA channels
1-3-1	RAM problem detected
1-3-3
1-3-4	Error when testing the first 64 KB of RAM
1-4-1	Faulty motherboard
1-4-2	RAM problems found
1-4-3	Error system timer
1-4-4	Error accessing I/O port. The error may be caused by a peripheral device using this port for its work.
3-1-1	Second DMA channel initialization error
3-1-2	First DMA channel initialization error
3-1-4	Faulty motherboard
3-2-4	Keyboard controller error
3-3-4	Video memory test error
4-2-1	System timer error
4-2-3	Error during operation of line A20. Faulty keyboard controller
4-2-4	Error while running in protected mode. Possibly a defective CPU
4-3-1	Error while testing RAM
4-3-4	Real time clock error
4-4-1	Serial port test error. Can be caused by a device that uses the serial port for its work
4-4-2	Parallel port test failed. Can be caused by a device that uses a parallel port for its work
4-4-3	Error while testing math coprocessor

AST BIOS signals:

Number of signals	Designation	Solution
1 short	Error while checking processor registers. Processor failure
2 short	Keyboard controller buffer error. Keyboard controller failure
3 short	Keyboard controller reset error. Malfunction of the keyboard controller or system board
4 short	Keyboard communication error
5 short	Keyboard input error
6 short	System board error
9 short	BIOS ROM checksum mismatch. Faulty BIOS ROM chip
10 short	System timer error. The system timer chip is faulty.
11 short	Chipset error
12 short	Power Management Register Error in Non-Volatile Memory
1 long	DMA controller error 0. Faulty DMA controller chip channel 0
1 long + 1 short	DMA controller error 1. Faulty DMA controller chip channel 1
1 long + 2 short	Error damping the reverse motion of the vertical scan. Possibly faulty video adapter
1 long + 3 short	Error in video memory. Faulty video adapter memory
1 long + 4 short	Video adapter error. Faulty video adapter
1 long + 5 short	Memory error 64K
1 long + 6 short	Failed to load interrupt vectors. BIOS was unable to load interrupt vectors into memory
1 long + 7 short	Failed to initialize video hardware
1 long + 8 short	Video memory error

Well, everything, I posted more or less common BIOS types with error codes. There will be questions, please contact!

Compaq BIOS:

	error message	Description
		System is booting properly
	BIOS ROM checksum error	The contents of the BIOS ROM to not match the expected contents. If possible, reload the BIOS from the PAQ

		Check the video adapter and ensure it's seated properly. If possible, replace the video adapter
7 beeps (1 long, 1s, 1l, 1 short, pause, 1 long, 1 short, 1 short)		The AGP video card is faulty. Reseat the card or replace it outright. This beep pertains to Compaq Deskpro systems
1 long neverending beep		memory error. Bad RAM. Replace and test
		Reseat RAM then retest; replace RAM if failure continues

IBM Desktop BIOS:

	error message	Description
		System is booting properly
	initialization error	Error code is displayed
	System board error
	Video adapter error
	EGA/VGA adapter error
	3270 keyboard adapter error
	power supply error	Replace the power supply
	power supply error	Replace the power supply
		Replace the power supply

IBM Thinkpad BIOS:

Beeps/Error	Description
continuous beeping	System board failure
one beep; Unreadable, blank or flashing LCD	LCD connector problem; LCD backlight inverter failure; video adapter faulty; LCD assembly faulty; System board failure; power supply failure
one beep; Message "Unable to access boot source"	boot device failure; system board failure
One long, two short beeps	System board failure; video adapter problem; LCD assembly failure
One long, four short beeps	low battery voltage
One beep every second	low battery voltage
Two short beeps with error codes	POST error message
	System board failure

IBM Intellistation BIOS:

Beep error code:	Action / Run diagnostics on the following components:
1-1-3 CMOS read/write error	1. Run Setup 2.System Board
1-1-4 ROM BIOS check error	1.System Board
1-2-X DMA error	1.System Board
1-3-X	1.Memory module 2.System Board
1-4-4	1.Keyboard 2.System Board
1-4-X Error detected in first 64 KB of RAM.	1.Memory module 2.System Board
2-1-1, 2-1-2	1. Run Setup 2.System Board
2-1-X First 64 KB of RAM failed.	1.Memory module 2.System Board
2-2-2	2.System Board
2-2-X First 64 KB of RAM failed.	1.Memory module 2.System Board
2-3-X	1.Memory module 2.System Board
2-4-X	1. Run Setup 2.Memory module 3.System Board
3-1-X DMA register failed.	1.System Board
3-2-4 Keyboard controller failed.	1.System Board 2 Keyboard
3-3-4 Screen initialization failed.	1. Video Adapter (if installed) 2.System Board 3.Display
3-4-1 Screen retrace lest detected an error.	1. Video Adapter (if installed) 2.System Board 3.Display
3-4-2 POST is searching for video ROM.	1. Video Adapter (if installed) 2.System Board
4	1. Video Adapter (if installed) 2.System Board
All other beep code sequences.	1.System Board
One long and one short beep during POST. Base 640 KB memory error or shadow RAM error.	1.Memory module 2.System Board
One long beep and two or three short beeps during POST.(Video error)	1. Video Adapter (if installed) 2.System Board
Three short beeps during POST.	1. See "System board memory" on page 62. 2.System Board
continuous beep.	1.System Board
Repeating short beeps.	1. Keyboard stuck key? 2. Keyboard cable 3.System Board

Mylex BIOS:

	error message	Description
		System is booting normally
	Video adapter error	The video adapter is either faulty or not seated properly. Check the adapter
	keyboard controller error	The keyboard controller IC is faulty. Replace the IC if possible
		The keyboard controller IC is faulty or the keyboard is faulty. Replace the keyboard, if problem still persists, replace the keyboard controller IC
		The programmable interrupt controller is faulty. Replace the IC if possible
		The programmable interrupt controller is faulty. replace the IC if possible
	DMA page register error	The DMA controller IC is faulty. Replace the IC if possible
	RAM refresh error

	RAM parity error
	DMA controller 0 error	The DMA controller IC for channel 0 has failed
		The CMOS RAM has failed
	DMA controller 1 error	The DMA controller IC for channel 1 has failed
	CMOS RAM battery error	The CMOS RAM battery failed. If possible, replace the CMOS or battery
	CMOS RAM checksum error	The CMOS RAM has failed. If possible, replace the CMOS
	BIOS ROM checksum error	The BIOS ROM has failed. If possible replace the BIOS or upgrade it

Mylex 386 BIOS:

	error message	Description
		System is booting normally
	Video adapter failure	Either the video adapter is faulty, not seated properly or is missing
1 long, 1 short, 1 long	keyboard controller error	Either the keyboard controller IC is faulty or the system board circuitry is faulty
1 long, 2 short, 1 long		Either the keyboard controller is faulty or the system board circuitry is faulty
1 long, 3 short, 1 long
1 long 4 short, 1 long		The programmable interrupt controller IC is faulty
1 long, 5 short, 1 long	DMA page register error	The DMA controller IC 1 or 2 is faulty or the system board circuitry is faulty
1 long, 6 short, 1 long	RAM refresh error
1 long, 7 short, 1 long
1 long, 8 short, 1 long	RAM parity error
1 long, 9 short, 1 long	DMA controller 1 error	The DMA controller for channel 0 is faulty or the system board circuitry is faulty
1 long, 10 short, 1 long		Either the CMOS RAM is faulty. Replace the CMOS
1 long, 11 short, 1 long	DMA controller 2 error	The DMA controller for channel 1 is faulty or the system board circuitry is faulty
1 long, 12 short, 1 long	CMOS RAM battery error	The CMOS RAM battery is faulty or the CMOS RAM is bad. Replace the battery if possible
1 long, 13 short, 1 long	CMOS checksum error	The CMOS RAM is faulty
1 long 14 short, 1 long	BIOS ROM checksum failure	The BIOS ROM checksum is faulty. Replace the BIOS or upgrade

Phoenix ISA/MCA/EISA BIOS:

The beep codes are represented in the number of beeps. E.g. 1-1-2 would mean 1 beep, a pause, 1 beep, a pause, and 2 beeps.

With a Dell computer, a 1-2 beep code can also indicate that a bootable add-in card is installed but no boot device is attached. For example, in you insert a Promise Ultra-66 card but do not connect a hard drive to it, you will get the beep code. I verified this with a SIIG (crap -- avoid like the plague) Ultra-66 card, and then confirmed the results with Dell.

	error message	Description
	CPU test failure	The CPU is faulty. Replace the CPU
	System board select failure	The motherboard is having an undetermined fault. Replace the motherboard
	CMOS read/write error	The real time clock/CMOS is faulty. Replace the CMOS if possible
	Extended CMOS RAM failure	The extended portion of the CMOS RAM has failed. Replace the CMOS if possible
	BIOS ROM checksum error	The BIOS ROM has failed. Replace the BIOS or upgrade if possible
		The programmable interrupt timer has failed. Replace if possible

	DMA read/write failure	The DMA controller has failed. Replace the IC if possible
	RAM refresh failure	The RAM refresh controller has failed
	64KB RAM failure	The test of the first 64KB RAM has failed to start
	First 64KB RAM failure	The first RAM IC has failed. Replace the IC if possible
	First 64KB logic failure	The first RAM control logic has failed
	address line failure	The address line to the first 64KB RAM has failed
	Parity RAM failure	The first RAM IC has failed. Replace if possible
	EISA fail-safe timer test	Replace the motherboard
	EISA NMI port 462 test	Replace the motherboard
	64KB RAM failure	bit0; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 1; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit2; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 3; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 4; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 5; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 6; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 7; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 8; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 9; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 10; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 11; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 12; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 13; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 14; This data bit on the first RAM IC has failed. Replace the IC if possible
	64KB RAM failure	bit 15; This data bit on the first RAM IC has failed. Replace the IC if possible
	Slave DMA register failure	The DMA controller has failed. Replace the controller if possible
	Master DMA register failure	The DMA controller had failed. Replace the controller if possible
	Master interrupt mask register failure
	Slave interrupt mask register failure	The interrupt controller IC has failed
	Interrupt vector error	The BIOS was unable to load the interrupt vectors into memory. Replace the motherboard

	keyboard controller failure
	CMOS RAM power bad	Replace the CMOS battery or CMOS RAM if possible
	CMOS configuration error	The CMOS configuration has failed. Restore the configuration or replace the battery if possible

	Video memory failure	There is a problem with the video memory. Replace the video adapter if possible
	Video initialization failure	There is a problem with the video adapter. Reseat the adapter or replace the adapter if possible
		The system "s timer IC has failed. Replace the IC if possible
	shutdown failure	The CMOS has failed. Replace the CMOS IC if possible
	Gate A20 failure	The keyboard controller has failed. Replace the IC if possible
	Unexpected interrupt in protected mode	This is a CPU problem. Replace the CPU and retest
	RAM test failure	System RAM addressing circuitry is faulty. Replace the motherboard
	Interval timer channel 2 failure	The system timer IC has failed. Replace the IC if possible
	Time of day clock failure	The real time clock/CMOS has failed. Replace the CMOS if possible
	serial port failure	A error has occurred in the serial port circuitry
	Parallel port failure	A error has occurred in the parallel port circuitry
	Math coprocessor failure	The math coprocessor has failed. If possible, replace the MPU

	Description
	Verify real mode

	Initialize system hardware
	Initialize chipset registers with initial values
	Set in POST flag
	Initialize CPU registers
	Initialize cache to initial values

	Initialize power management
	Load alternative registers with initial POST values
	Jump to UserPatch0
	initialize timer initialization
	8254 timer initialization
	8237 DMA controller initialization
	Reset Programmable Interrupt Controller
	Test DRAM refresh
	Test 8742 Keyboard Controller
	Set ES segment register to 4GB

	Clear 512K base memory
	Test 512K base address lines
	Test 51K base memory
	Test CPU bus-clock frequency
	CMOS RAM read/write failure (this commonly indicates a problem on the ISA bus such as a card not seated)
	Reinitialize the chipset
	Shadow system BIOS ROM
	Reinitialize the cache
	Autosize the cache
	Configure advanced chipset registers
	Load alternate registers with CMOS values
	Set initial CPU speed
	Initialize interrupt vectors
	Initialize BIOS interrupts
	Check ROM copyright notice
	Initialize manager for PCI Options ROMs
	Check video configuration against CMOS
	Initialize PCI bus and devices
	initialize all video adapters in system
	Shadow video BIOS ROM
	Display copyright notice
	Display CPU type and speed

	Set key click if enabled

	Test for unexpected interrupts
	Display prompt "Press F2 to enter setup"
	Test RAM between 512K and 640K
	Test expanded memory
	Test extended memory address lines
	Jump to UserPatch1

	Configure advanced cache registers
	Enable external and CPU caches
	Initialize SMI handler
	Display external cache size
	Display shadow message
	Display non-disposable segments
	Display error messages
	Check for configuration errors
	Test real-time clock
	Check for keyboard errors
	Setup hardware interrupt vectors
	Test coprocessor if present
	Disable onboard I/O ports
	Detect and install external RS232 ports
	Detect and install external parallel ports
	Reinitialize onboard I/O ports
	Initialize BIOS Data Area
	Initialize Extended BIOS Data Area
	Initialize floppy controller
	Initialize hard disk controller
	Initialize local bus hard disk controller
	Jump to UserPatch2
	Disable A20 address line
	Clear huge ES segment register
	Search for option ROMs
	Shadow option ROMs
	Setup power management
	Enable hardware interrupts



	Scan for F2 keystroke

	Clear in-POST flag
	Check for errors
	POST done - prepare to boot operating system

	Check password (optional)
	Clear global descriptor table
	Clear parity checkers
	Check virus and backup reminders
	Try to boot with INT 19
	Interrupt handler error
	Unknown interrupt error
	pending interrupt error
	Initialize option ROM error

	Extended Block Move
	Shutdown 10 error
	Keyboard Controller failure (most likely problem is with RAM or cache unless no video is present)
	Initialize the chipset
	Initialize refresh counter
	Check for Forced Flash

	Do a complete RAM test
	Do OEM initialization
	Initialize interrupt controller
	Read in bootstrap code
	Initialize all vectors
	Initialize the boot device
	Boot code read OK

Quadtel BIOS:

	error messages	Description
		System is booting normally
		The CMOS RAM is faulty. Replace the IC if possible
		The video adapter is faulty. Reseat the video adapter or replace the adapter if possible
	Peripheral controller error	One or more of the system peripheral controllers is bad. Replace the controllers and retest

How many PC users there are in the world, almost the same number of computers will not start sooner or later for various reasons. If you have a speaker in your case, then, as a rule, a single short signal is heard when the system starts successfully. However, if you hear any other sequence of beeps when you start your computer, this guide will help you figure out what the problem is.

How it works

When you turn on the computer, the programs that are part of the BIOS (basic input / output system) of the motherboard perform a self-test hardware PC. This self-test is called POST (Power-On Self-Test).

POST screen

While the POST screen is displayed on the monitor, BIOS utilities all components are checked step by step. As soon as a problem is detected, for example, with RAM or a video card, the BIOS sends a signal to the speaker connected in the case, and the latter issues a sequence of error signals.

Speaker

If there is no speaker in the PC case, then you will not be able to find out the error code by the sound signal in other ways!

In addition, you need to know the exact manufacturer and version. motherboard BIOS fees, because codes sound bugs(beep codes) for each BIOS may be different.

Table of sound signals

AMI BIOS (American Megatrends, Inc.)

	Error Description
1 short
2 short	RAM parity error or scanner or printer not turned off
3 short	Error in the first 64 KB of RAM
4 short	The system timer is faulty. Replace motherboard.
5 short	CPU issues
6 short
7 short	Motherboard problems
8 short	Video card memory error
9 short	BIOS checksum is incorrect
10 short	CMOS write error
11 short	Cache error located on the motherboard
1 long, 1 short	Problems with the power supply
1 long, 2 short
1 long, 3 short	Video card error (Mono-CGA). Faulty memory slots. Replace motherboard.
1 long, 4 short	No video card
1 long, 8 short	Problems with the video card or the monitor is not connected
3 long	RAM - Read/Write test completed with an error. Reinstall the memory or replace with a good module.
5 short, 1 long	RAM is not installed or not installed as recommended by the motherboard manufacturer
Continuous beep	Power supply failure or computer overheating

Award BIOS

Sequence sound signals	Error Description
1 short	Successful POST: no errors found, computer healthy
2 short	Minor bugs found. The monitor screen prompts you to enter the CMOS Setup Utility program and correct the situation. Check the reliability of the fastening of the cables in the connectors of the hard drive and the motherboard.
3 long	Keyboard controller initialization error
1 short, 1 long	Random Access Memory (RAM) Error
1 long, 2 short	Video card error
1 long, 3 short	No video card or video memory error
1 long, 9 short	Error while reading from ROM
Repetitive short	Problems with the power supply or RAM
recurring long	RAM problems
Repeating with high-low frequency	CPU issues
Continuous	Problems with the power supply

IBM BIOS

Beep sequence	Error Description
1 short	Successful POST: no errors found, computer healthy
1 beep and blank screen	Faulty video system
2 short	Faulty video system
3 long	Faulty motherboard (keyboard controller error), poor or missing connection to the RAM bar
1 long, 1 short	Faulty motherboard
1 long, 2 short	Faulty video system (Mono/CGA)
1 long, 3 short	Faulty video system (EGA/VGA)
Repetitive short	Faults are related to the power supply or motherboard
Continuous	Problems with the power supply or motherboard
Missing	Faulty power supply, motherboard, speaker, or no CPU power

Quadtel BIOS

Compaq BIOS

Beep sequence	Error Description
1 short	Successful POST: no errors found, computer healthy
1 long, 1 short	CMOS BIOS memory checksum error. Possibly the ROM battery is dead.
2 short	global error
1 long, 2 short	Video card initialization error. Check if the video card is installed correctly.
7 beeps (1 long, 1 s, 1?, 1 short, pause, 1 long, 1 short, 1 short)	AGP video card failure. Check if the installation is correct.
1 long standing	RAM error. Try rebooting.
1 short, 2 long	RAM failure. Reboot via Reset.

AST BIOS

Beep sequence	Error Description
1 short	Error while checking processor registers. Processor failure.
2 short	Keyboard controller buffer error. Keyboard controller malfunction.
3 short	Keyboard controller reset error. Malfunction of the keyboard controller or system board.
4 short	Keyboard communication error
5 short	Keyboard input error
6 short	System board error
9 short	BIOS ROM checksum mismatch. Faulty BIOS ROM chip.
10 short	System timer error. The system timer chip is faulty.
11 short	System logic chip (chipset) error
12 short	Power Management Register Error in Non-Volatile Memory
1 long	DMA controller 0 error. Faulty channel 0 DMA controller chip.
1 long, 1 short	DMA controller error 1. Faulty channel 1 DMA controller chip.
1 long, 2 short	Error damping the reverse motion of the vertical scan. The video card may be faulty.
1 long, 3 short	Error in video memory. Faulty video card memory.
1 long, 4 short	Video adapter error. Bad video card.
1 long, 5 short	Memory error 64K
1 long, 6 short	Failed to load interrupt vectors. The BIOS was unable to load interrupt vectors into memory.
1 long, 7 short	Failed to initialize video subsystem
1 long, 8 short	Video memory error

In DELL BIOS and Phoenix BIOS, which are presented below, beep codes are arranged in a sequence of beeps. Let's say 1-1-2 means 1 beep, pause, 1 beep, pause, and 2 beeps.

Dell BIOS

Phoenix BIOS

Beep sequence	Error Description
1-1-2	Processor test error. The processor is defective. Replace processor.
1-1-3	Error writing / reading data to / from CMOS memory
1-1-4	An error was detected while calculating the checksum of the BIOS content
1-2-1
1-2-2 or 1-2-3	DMA controller initialization error
1-3-1	Error initializing the RAM regeneration scheme
1-3-3 or 1-3-4	Error initializing the first 64 KB of RAM
1-4-1	Motherboard initialization error
1-4-2
1-4-3
1-4-4	Write/read error to/from one of the I/O ports
2-1-1	An error was detected while reading/writing the 0th bit (in hexadecimal representation) of the first 64 KB of RAM
2-1-2	An error was detected while reading/writing the 1st bit (in hexadecimal representation) of the first 64 KB of RAM
2-1-3	An error was detected while reading/writing the 2nd bit (in hexadecimal representation) of the first 64 KB of RAM
2-1-4	An error was detected while reading/writing the 3rd bit (in hexadecimal representation) of the first 64 KB of RAM
2-2-1	An error was detected while reading/writing the 4th bit (in hexadecimal representation) of the first 64 KB of RAM
2-2-2	An error was detected while reading/writing the 5th bit (in hexadecimal representation) of the first 64 KB of RAM
2-2-3	An error was detected while reading/writing the 6th bit (in hexadecimal representation) of the first 64 KB of RAM
2-2-4	An error was detected while reading/writing the 7th bit (in hexadecimal representation) of the first 64 KB of RAM
2-3-1	An error was detected while reading/writing the 8th bit (in hexadecimal representation) of the first 64 KB of RAM
2-3-2	An error was detected while reading/writing the 9th bit (in hexadecimal representation) of the first 64 KB of RAM
2-3-3	An error was detected while reading/writing the 10th bit (in hexadecimal representation) of the first 64 KB of RAM
2-3-4	An error was detected while reading/writing the 11th bit (in hexadecimal representation) of the first 64 KB of RAM
2-4-1	An error was detected while reading/writing the 12th bit (in hexadecimal representation) of the first 64 KB of RAM
2-4-2	An error was detected while reading/writing the 13th bit (in hexadecimal representation) of the first 64 KB of RAM
2-4-3	An error was detected while reading/writing the 14th bit (in hexadecimal representation) of the first 64 KB of RAM
2-4-4	An error was detected while reading/writing the 15th bit (in hexadecimal representation) of the first 64 KB of RAM
3-1-1	Second DMA channel initialization error
3-1-2 or 3-1-4	First DMA channel initialization error
3-2-4	Keyboard controller initialization error
3-3-4	Video memory initialization error
3-4-1	There were serious problems when trying to access the monitor
3-4-2	Can't initialize graphics card BIOS
4-2-1	System timer initialization error
4-2-2	Testing completed
4-2-3	Keyboard controller initialization error
4-2-4	Critical error during the transition CPU into protected mode
4-3-1	Memory initialization error
4-3-2	First timer initialization error
4-3-3	Second timer initialization error
4-4-1	Error initializing one of the serial ports
4-4-2	Parallel port initialization error
4-4-3	Math coprocessor initialization error
Long, incessant signals	Faulty motherboard
The sound of a siren high on low frequency	The video card is faulty, check the electrolytic tanks for leaks or replace everything with new ones that are known to be good
continuous signal	Not connected (faulty) CPU cooler

As necessary, the article will be supplemented.

tables BIOS signals taken from Wikipedia.