bios signals. sound short and long beeps when turning on the PC

The BIOS is responsible for checking the functionality of the main components of the computer before each power-up. Before the OS is loaded, BIOS algorithms check the hardware for critical errors. If any are found, then instead of loading the operating system, the user will receive a series of certain sound signals and, in some cases, display information on the screen.

BIOS is actively developed and improved by three companies - AMI, Award and Phoenix. Most computers have built-in BIOS from these developers. Depending on the manufacturer, sound alerts may vary, which is sometimes not very convenient. Let's take a look at all the computer's turn-on signals from each developer.

AMI beeps

With this developer, sound alerts are distributed by beeps - short and long signals.

Sound messages are given without pauses and have the following meanings:

• The absence of a signal means a malfunction of the power supply or the computer is not connected to the network;
• 1 short signal - accompanied by the start of the system and means that no problems were detected;
• 2 and 3 short messages are responsible for certain malfunctions with RAM. 2 signal - parity error, 3 - the inability to start the first 64 KB of RAM;
• 2 short and 2 long signal - malfunction of the floppy disk controller;
• 1 long and 2 short or 1 short and 2 long- video adapter failure. Differences may be due to different BIOS versions;
• 4 short signals indicate violations of the system timer. It is noteworthy that in this case the computer may start, but the time and date in it will be knocked down;
• 5 short messages indicate CPU inoperability;
• 6 short signals indicate a problem with the keyboard controller. However, in this case, the computer will start, but the keyboard will not work;
• 7 short messages - a malfunction of the system board;
• 8 short beeps indicate an error in the video memory;
• 9 short signals is a fatal error when starting the BIOS itself. Sometimes restarting the computer and / or resetting BIOS settings helps to get rid of this problem;
• 10 short messages indicate an error in the CMOS memory. This type of memory is responsible for correctly saving the BIOS settings and starting it when turned on;
• 11 short beeps in a row means that there is a serious problem with the cache memory.

Audible Signals Award

Sound alerts in the BIOS from this developer are somewhat similar to signals from the previous manufacturer. However, Award has fewer of them.

Let's decipher each of them:

• The absence of any sound alerts may indicate problems with the connection to the mains or problems with the power supply;
• 1 short a non-repeating signal is accompanied by a successful launch of the operating system;
• 1 long the signal indicates problems with RAM. This message can be played either once or repeated for a certain period of time, depending on the motherboard model and BIOS version;
• 1 short the signal indicates problems with the power supply or a short circuit in the power transmission circuit. It will go continuously or repeat at a certain interval;
• 1 long and 2 short alerts indicate the absence of a graphics adapter or the inability to use video memory;
• 1 long signal and 3 short warn about a malfunction of the video adapter;
• 2 short signals without pauses indicate small errors that occurred during startup. Data on these errors is displayed on the monitor, so you can easily deal with their solution. To continue loading the OS, you will have to click on F1 or Delete, more detailed instructions will be displayed on the screen;
• 1 long message and subsequent 9 short indicate a malfunction and / or failure to read BIOS chips;
• 3 long signals indicate a problem with the keyboard controller. However, the operating system will continue to load.

Phoenix beeps

This developer has made a large number of different combinations of BIOS signals. Sometimes this variety of messages causes problems for many users to identify the error.

In addition, the messages themselves are quite confusing, as they consist of certain sound combinations of different sequences. The decoding of these signals is as follows:

• 4 short—2 short—2 short messages mean the completion of component testing. After these signals, the operating system will start loading;
• 2 short—3 short—1 short a message (the combination is repeated twice) indicates errors in the processing of unexpected interrupts;
• 2 short—1 short—2 short—3 short a signal after a pause indicates an error when checking the BIOS for copyright compliance. This error is more common after updating the BIOS or when you first start the computer;
• 1 short—3 short—4 short—1 short the signal reports an error that was made when checking the RAM;
• 1 short—3 short—1 short—3 short messages occur when there is a problem with the keyboard controller, but the operating system will continue to load;
• 1 short—2 short—2 short—3 short beeps warn of an error in the calculation of the checksum when starting the BIOS .;
• 1 short and 2 long beeps indicate an error in the operation of adapters that can have their own BIOS built into them;
• 4 short—4 short—3 short you will hear a beep when there is an error in the math coprocessor;
• 4 short—4 short—2 long a signal will report an error in the parallel port;
• 4 short—3 short—4 short signals indicate a failure of the real time clock. With this failure, you will be able to use the computer without any difficulty;
• 4 short—3 short—1 short the signal indicates a problem with the RAM test;
• 4 short—2 short—1 short the message warns of a fatal failure in the central processor;
• 3 short—4 short—2 short you will hear if there are any problems with the video memory or the system cannot find it;
• 1 short—2 short—2 short beeps indicate a failure in reading data from the DMA controller;
• 1 short—1 short—3 short beeps will sound when an error is associated with the operation of CMOS;
• 1 short—2 short—1 short a beep indicates a problem with the system board.

It is quite familiar to many users to hear a beep from the system unit when the computer is turned on. A single short signal indicates that "everything is in order." And if, for example, 1 long signal or a series of sounds sounds instead of it, then it immediately becomes clear that there is a problem. This emits signals to the BIOS, the same program that runs first and tests all components of the computer (from the CPU to the monitor).

The BIOS emits signals during the initial testing of the components of the system unit, while the video card has not yet been initialized, which can display certain text and tabular data on the monitor. With the help of them, you can determine the faulty unit inside the system unit or identify poor contact of external connections.

BIOS errors are encoded into a specific combination of long and short beeps. Moreover, all of them are the same for motherboards of different years of production from almost all manufacturers (from the most famous to "noname"). BIOS audio error codes have a detailed description in the instructions for the motherboard, however, often in English.

The BIOS can make sounds on a mandatory condition: a small, as it is called, system speaker must be connected to the motherboard. Otherwise, BIOS errors will go unnoticed and the user will see only a dark monitor screen.

Sound signals: what is needed to decipher them?

If a single BIOS signal indicates a normal computer startup, then a series of the same short or long sounds (combinations of them) indicates the detection of problems, moreover, of a hardware nature. Then you have to open the cover of the system unit. And even if the user does not interfere with the PC device himself, for example, due to the presence of factory seals on the screws of the cover, decoding these signals will help determine the source of the problem.

Different computer manufacturers may have different beep sounds due to the fact that they use different BIOS versions. Nevertheless, among them you can find those that are typical and most commonly used.

Diagnostics using BIOS sound signals is one of the most effective methods, without the use of special test boards (such as POST-card), therefore, despite the systematic development of production technologies, all motherboards come with a small speaker or, at least, with a connector for its connections.

Sound signals are emitted in the presence of a working power supply and speaker. If they are faulty, then no diagnostics will work. A speaker malfunction can only be determined by replacing it with a known-good copy, which is not always available.

When everything works as intended, then in order to decrypt error codes, you should use a special list that indicates the typical signals for this BIOS version.

Award BIOS beep codes

The most common among the numerous BIOS versions are the versions from the Award developer, who has been making his programs for motherboards since the days when the Pentium trademark did not even exist.

The list of typical signals that are the same for all versions of the Award BIOS is as follows:

1. Continuous signal. Breakdown in the power supply. The easiest way to check if this is the case is by replacing the power supply with a known-good copy.
2. 2 short. The BIOS pays attention to minor errors, which, nevertheless, require the correct parameters to be entered, for example, by loading the standard factory settings.
3. 3 long. The problem is in the keyboard block on the motherboard. The cause can be either a short circuit in the keyboard or connecting cable, or in the motherboard (connector, electronics, electrically conductive dust, etc.).
4. 1 long, 1 short. BIOS errors cause RAM modules. The easiest way to fix the problem is to pull out the modules, blow out the accumulated dust from the connector, clean the contacts on the modules themselves and insert them back into the connector. You can leave only one module for the test period and, if necessary, change them, determining which one causes sound signals.
5. 1 long, 2 short. . For some models of video cards, such codes are issued when there is poor contact in the monitor connector, when at the moment the BIOS is turned on it cannot determine whether there is a connection with it. To fix the problem, you can do with the video card in the same way as with the RAM in the previous paragraph.
6. 1 long, 3 short. The BIOS was unable to initialize the keyboard, which may indicate a malfunction of the keyboard itself, as well as the connector or electronics of the motherboard. The easiest way is to temporarily disable the keyboard, then it will immediately become clear whether it is the source of the problem.
7. 1 long, 9 short. Malfunction of the BIOS chip itself. You should just turn off the computer for a while and try turning it on again. If the situation persists and the BIOS error codes do not change, then you should replace the motherboard or try to flash the chip using a special programmer.
8. 1 long, constantly repeating. Error initializing memory. It is necessary to replace the modules or at least clean the contacts in the connector and try again.
9. 1 short, constantly repeating. Incorrect operation of the power supply. In any case, only a replacement with a serviceable unit or repair of an existing unit will help. Bad contacts are almost never found here due to the large connectors compared to other components of the system unit.

AMI BIOS beep codes

The AMI developer is less common in the BIOS of motherboards than its competitor Award, but, nevertheless, he has firmly occupied his own, albeit small, niche in this market, so you should be ready to meet with his audio signal encoding system.

Deciphering the encoding of audio signals:

1. 2 short. The error is caused by incorrect operation of the RAM. In any case, you should start by cleaning the connectors from dust, even if you plan to immediately install new modules to replace the "suspicious" ones.
2. 3 short. Like the previous paragraph, indicates a malfunction of the RAM module.
3. 4 short. The system timer, which is the basis for the operation of all other components of the motherboard, is faulty. The only thing that can be done without replacing it is to turn off the system unit for a while.
4. 5 short. An error occurred while initializing the CPU. You can either turn off the system unit for a while, or remove the cooling system from the processor, pull it out of the socket, and then insert it back. If nothing helps, then you have to change the processor.
5. 6 short. The keyboard or its processing unit on the motherboard is faulty. To clarify the source, you can temporarily disable the keyboard, replace it with a known-good copy.
6. 7 short. Fault in the motherboard. In such a situation, a careful external examination of the board for the presence of contact-closing debris can help.
7. 8 short. Bad video card. You should replace it or, in extreme cases, clean the contacts in the connector. You can temporarily enable the built-in video card and check the operation of the computer with it (if, of course, it is available).
8. 1 long, 2 short. Error while initializing video card. The elimination methods are the same as in the previous paragraph.
9. 1 long, 3 short. Fault in the video card.
10. 1 long, 8 short. The problem is either in the video card or in the monitor.

The following lists of BIOS signals are the basis for diagnosing a computer when there are no other options. In most cases, they allow you to determine the source of the problem, which can simply be replaced with a known-good unit.

If you heard 3 short beeps during the BIOS equipment check procedure, this means that far from everything is in order in your computer. However, it will be difficult for you to find the cause of the malfunction until you look in the BIOS signal table and find out what this signal means.

As you know, different BIOS manufacturers use different tables of sound error messages, and they do not always coincide with each other. As for the situation when you hear 3 short beeps when loading the BIOS, it appears only in some versions of the BIOS.

One such BIOS version is the AMI BIOS. As a rule, if your computer's motherboard is equipped with a similar version of the BIOS, then an informational message containing three short beeps means an error when checking the first 64 KB of RAM.

At present, when the amount of RAM in modern computers is measured in gigabytes, not kilobytes, the chance of receiving such an informational message is small. However, it may appear on some older computers. If such an error still occurs, then you should try to restart the computer using the Reset button. If three short beeps still remain, then you should try to check the reliability of fastening the memory modules in the slots. In the same case, if all the above measures did not bring results, then it will be necessary to change the memory modules.

This signal has a slightly different meaning - three short beeps, it has in the BIOS from AST. In this BIOS, a similar sequence of sounds means something else - a malfunction of the keyboard controller.

If you hear three short beeps when checking the hardware carried out by AST BIOS, then you should not immediately panic. It is possible that after you reboot again, these signals will disappear and you will be able to use the computer again. If this operation did not help restore the computer to working capacity, then you will most likely have to change the keyboard controller, or even the motherboard itself.

Today we will talk about the situation when the computer, when turned on, emits 1 long signal, possibly after a while, a repeating signal and at the same time does not display anything on the screen.

In this situation, there are definitely problems with the equipment. Depending on the motherboard model and BIOS manufacturer, 1 long beep can mean various problems.

Phoenix BIOS thus notifies the user of a fan failure in the CPU cooler. In the Award BIOS, such a combination indicates problems with the power supply. And for the Compaq BIOS, this means a violation of the correct functioning of the RAM.

The IBM BIOS notifies you of video problems with one continuous beep. In some cases, the user can fix such a breakdown on their own. You just need to check how correctly the video card is in the motherboard slot. Perhaps the device should be tweaked a little, and the annoying signal will disappear.

AST BIOS in this case indicates a microcontroller failure. To be more precise, the signal indicates an error detected at the time of checking the first DMA channel. Often, to correct this situation, the user has to change the entire motherboard.

Solutions

So, the first thing to solve this problem is to try to get and install the RAM in place, after wiping its contacts with an eraser. Ideally, take another known working memory and insert it instead of your own.

One of the possible reasons for this sequence of signals is RAM

If after that the problem has not gone away, check if the processor fan is connected to the motherboard properly and if it is not jammed. To do this, try to scroll it with your finger. The computer must be powered off.

Checking the correct connection of the processor cooler

The next step in eliminating one long BIOS signal is to install a known working power supply, which you can temporarily borrow from friends or acquaintances.

The power supply is one of the possible causes of 1 long BIOS signal

The last step in an attempt to eliminate the prolonged BIOS signal at boot is to try to remove / install the video card by rubbing the contacts with an eraser.

Installing / removing a video card to solve the problem of one short and two long BIOS signals when the computer is turned on

If, after all the steps described, you were unable to start the computer, then most likely you will have to change the entire motherboard.

American Megatrends Inc. (AMI)

The checkpoints of the POST procedures performed in AMIBIOS were revised and supplemented in 1995 and have not undergone significant changes to date. The first description of POST codes or as AMI calls them - "check points" in their current form appeared in connection with the release of the V6.24 kernel, 15/07/95. Some changes have been made in AMIBIOS V7.0 and are reflected in this document.

Features of AMIBIOS startup procedures execution

If during the start process data 55h, AAh appears in the diagnostic port, this information should not be compared with POST codes - we are dealing with a typical test sequence, the task of which is to check the integrity of the data bus.

At the start stage, the data output to the diagnostic port is specific to each platform. In some implementations, the first rendered code is associated with actions, which AMI calls chipset specific stuff. This procedure is accompanied by the output of the CCh value to port 80h and the performance of a number of actions to configure the system logic registers. As a rule, the CCh code occurs in those cases when the system logic from Intel is used, built on the basis of the PIIX controller - these are TX, LX, BX chipsets.

Some onboard I/O chips contain an RTC and a keyboard controller that are in a disabled state upon startup. The purpose of the BIOS is to initialize these board resources for future use. In this case, the first start procedure related to setting up the keyboard controller is accompanied by the output of the value 10h, then the RTC is initialized, as evidenced by the appearance of the DDh code in the diagnostic port. It should be noted that the failure of at least one of these resources will cause the system board as a whole to not start at the very first stage of the POST execution.

On some boards, the initialization process starts with putting the CPU into protected mode. In this case, following the first rendered code 43h, the POST execution continues as described in the AMIBIOS documentation - control is transferred to the D0h point.

Unpackaged initialization codes

Uncompressed Init Code Check Points

Flash ROM Overwriting Procedure Codes

Boot Block Recovery Codes

Unpacked system BIOS codes running in ShadowRAM

Runtime code is uncompressed in F000 shadow RAM

Features of running Device Initialization Manager

In addition to the above POST codes, event messages are output to the diagnostic port during the execution of the Device Initialization Manager (DIM). There are several breakpoints that display the initialization status of system or local buses.

The information is displayed in word format, the low byte of which matches the system POST code, and the high byte indicates the type of initialization procedure being performed. The high order tetrad in the high byte indicates the type of procedure to be executed, and the low order specifies the bus topology for its application.

Senior tetrad

Junior tetrad

If a system memory configuration error is detected, the DE code, the DF code, the configuration error code, which can take the following values, is output to port 80h sequentially in an endless loop:

2. Award BIOS V4.51PG Elite

AwardBIOS V4.51PG Elite

The dynamically developing company Award Software in 1995 offered a new at that time solution in the field of low-level software - AwardBIOS "Elite", better known as V4.50PG. The checkpoint service mode has not changed in either the widespread version V4.51 or the rare version V4.60. The suffixes P and G denote, respectively, the support of the PnP mechanism and the maintenance of power saving functions (Green Function).

POSTing to Shadow RAM

3. Award BIOS V6.0 Medallion

AwardBIOS V6.0 Medallion

The first mention of the Award Medallion BIOS, Version 6.0 dates back to May 12, 1999. The structure of the new product remained unchanged, retaining the early (Early), late (Late), and final (System) phases of hardware initialization. Significant changes have affected the algorithms for performing POST, which is reflected in the new encoding of checkpoints, significantly expanding their scope. However, the new BIOS did not have a place for outdated technologies such as EISA, and for this reason a number of POST codes were abolished.

Executing POST start routines from ROM

At the stage of early initialization, the BIOS program code is executed from the boot block (Boot Block) in Flash ROM, and is accompanied by the output of checkpoints 91h…FFh to the diagnostic port

BIOS recovery

POSTing to Shadow RAM

Late initialization is performed in RAM and continues until the user menu is called - CMOS Setup. This POST phase is characterized by the use of the E000h memory segment, in which the passage of checkpoints from 01h to 7Fh is processed.

Preparing tables, arrays and structures to start the operating system

Starting with code 82h, POST configures the system according to the CMOS settings. Its final phase is executed from the Shadow RAM area (segment E800h) and ends with the transfer of control to the operating system - code FFh.

A number of processes that take place in the Award Medallion BIOS are identified by special checkpoint groups. These include:

System Event codes - control points of system events.

Power Management Debug codes - checkpoints that occur during the execution of APM or ACPI services.

System Error codes - fatal error messages.

Debug codes for MP system - initialization points for multiprocessor platforms.

POST Fast Track Features

The user can select the "Quick Power On Self Test" option in CMOS Setup to reduce system boot time. In this case, the passage of POST will be accelerated by refusing to perform some procedures (Quick Boot).

The Quick Boot scheme replaces the late and final POST phases and does not affect the operation of the boot block. Award Software offers a non-standard codification of the executable POST fast-track procedures. Quick Boot starts with checkpoint 65h output to the diagnostic port and ends with POST code 80h. Control is then transferred to the operating system, displaying the usual Award BIOS code FFh.

Performing POST in Power Saving Mode

One of the platform states, when the contents of RAM is stored on the hard disk, is called Hibernate. In the ACPI specification ("Advanced Configuration and Power Interface Specification", Revision 2.0a dated 03/31/2002), it is defined as S4 (Non-Volatile Sleep) power saving mode. Returning to full functionality involves a special way of passing the POST.

The ACPI S4 operation scheme, as in the case of an accelerated start, replaces the late and final POST phases. An essential point is the check in the boot block of the start script. Depending on the ACPI state the system is in after the hardware Reset signal, a decision is made to exit the S4 state, which begins with the output of the 90h checkpoint to the diagnostic port and ends with the POST code 9Fh.

4. Phoenix BIOS 4.0 Release 6.0

Phoenix Technologies Ltd.

Phoenix Technologies, one of the leaders in the development of low-level software, timed the release of Windows95 with a new version of PhoenixBIOS 4.0. Support for the Intel Pentium processor family is reflected in the name of the interim revisions. One of the latest - Release 6.0 - formed the basis of all released BIOSes. Since Release 6.1, there have been no significant changes in the way POSTs are executed, and therefore this has not been reflected in the indication of breakpoints.

A distinctive feature of PhoenixBIOS is that if during the POST execution there are errors in testing 512 KB of main memory (codes 2Ch, 2Eh, 30h), additional information is output to port 80h in the format of a word, the bits of which identify the failed address line or data cell. For example, the code "2C 0002" means that a memory failure has been detected on address line 1. The code "2E 1020" in this case would mean that a failure has been detected on data lines 12 and 5 in the low byte of the memory data bus. On 386SX systems using a 16-bit data bus, an error cannot occur at runtime code 30h.

The output of the POST code to the diagnostic port is accompanied by the output of a sound signal to the system speaker. The scheme for generating an audio signal is as follows:

• Eight-bit code is converted into four two-bit groups
• The value of each group is incremented by one
• Based on the received value, a short beep is generated (for example: code 16h = 00 01 01 10 = 1-2-2-3)

Executing POST start routines from ROM

Fatal error messages

D0 Error caused by an exception (Exception error) D2 Calling the interrupt handling procedure from an unidentified source D4 Error related to violation of the protocol for issuing and removing interrupt requests D6 Exit protected mode with software generated reset D7 To save the state of the video adapter, more is required amount of memory than available in SMRAM D8 Error during software generation of processor reset pulse DA Loss of control when returning to Real Mode DC Exit protected mode with software generation of reset without reinitializing the interrupt controller DD Error during extended memory testing DE Keyboard controller error DF Line control error A20 19

Executing Procedures from the Boot Block

5. Inside BIOS Mobile Pro

Inside Software Corp.

The mobile systems market insider has firmly established himself where loyalty to tradition and a conservative approach to building a BIOS are required. Having inherited the source code from SystemSoft, the company is constantly working to improve it. The last of the MobilePRO revisions is actively used in Mitac and Clevo laptops, the documentation for which formed the basis of the Error Codes table - this is how Insyde Software calls POST execution checkpoints.

Boot Block Checkpoints

Despite the fact that Insyde Software created its first BIOS in 1992, the well-established boot block model - or Boot Loader, as the creators themselves called it - was finally formed only by the end of 1995. From that moment on, the starting procedure was numbered according to the version and date of creation.

The most significant point from the point of view of a service engineer investigating the process of booting a computer system with InsydeBIOS is the device for displaying diagnostic codes. Although, as a rule, the Boot Loader uses the Manufacture's Diagnostic Port 80h, which is standard in such cases, in some cases, checkpointing is performed only on the PIO Port (Parallel Input / Output port for diagnostic purpose), which is nothing more than parallel port 378h There are implementations in which diagnostic codes sent to port 80h are duplicated to the parallel port.

Performing POST procedures from RAM

Most modern InsydeBIOS solutions use 16-bit checkpoint mapping. For this, ports 80h and 81h are used, the latter of which is intended to extend the standard diagnostics.

The study of control points is hampered by their irregular construction, when processes that are different in meaning are accompanied by the same codes. In dual diagnostic systems, there are heterogeneities of a different order: some POST codes are displayed only in one of the ports without the usual duplication in such cases.