Posts Tagged ‘power on self test’
October 15th, 2009 | 
Author: Desktop Management Interface or DMI is a BIOS provided table that gives computer and BIOS information upon parsing in a standard form. It basically creates a framework that is used to manage and track desktop, server or notebook computer components. When you turn on the system, POST (Power-On Self Test) runs that verifies this table for integrity to pass the output information to the operating system. On occasion, you observe that this DMI verification doesn’t last and system gets stuck. Such system behavior is the general indicative of hard drive failure. The POST might fail to verify the DMI pool data and extend its check if encounters a failed hard drive. You should replace the damaged hard drive immediately and consult Data Recovery Service for further assistance and to recover the lost data.
To illustrate such issues, consider that you try to boot a computer system. The POST check runs as expected, but doesn’t complete as you receive the below error message:
“Verifying DMI Pool Data”
The boot process hangs after you receive the error message and you might need to forcefully shut down your computer.
Cause
Among other reasons, like incorrect BIOS settings for hard drive, loosely or improperly connected hard drive, BIOS corruption and incorrect boot sequence, the most probable reason for this error to occur is hard drive failure. A hard drive breakdown might occur due to wear and tear, read/write failure, PCB damage, motor failure and several other reasons.
Solution
You should first check for proper BIOS settings and correct boot sequence and make sure that the hard drive is properly connected to the computer. If this doesn’t resolve your issue, replace the hard drive as it might be damaged. For recovering lost data, if a healthy backup is not available, call a professional Data Recovery NJ service company.
Data Recovery Service is the manual aid provided to recover lost data from a physically crashed drive. It includes full-circle hardware and software techniques aim to repair or replace damaged hard drive internals. To provide data safety while opening and dealing with the failed hard drive, these companies use Clean Rooms technology.
Stellar Data Recovery Inc. is the pioneer company providing best and professional Data Recovery NJ. The company caters reliable disk recovery service for all brands, models and makes of hard drives including of SATA, SCSI, IDE, EIDE and PATA hard drives. It provides Class 100 Room facility and expert handling of failed drives.
Shaun Pattrik has 6 Years of Experience in the Software Technology researching with Stellar Info. System Ltd which offers data recovery, data recovery service, hard drive data recovery, data recovery NJ and data recovery New Jersey.
Article Source: Desktop Management Interface Verification Error While System Startup
Hard drive is considered to be a reliable storage media that stores your operating system, applications, documents and other data. To check its consistency and other connected hardware, a test is performed called POST (Power-On-Self-Test) as you turn on the computer system by BIOS.BIOS proceeds to next step of booting only when POST is successful. In case, if hard drive is faulty and is unable to start properly, POST halts the process of booting and you fail to access the stored information. You might interpret such events by few error messages that appear on screen while the process. Hard Drive Recovery is the solution to recover lost data from physically crashed hard drive, especially when there is no valid data backup available.
To illustrate this, consider that you attempt to boot your computer and its fails while the POST is running. In addition, you receive the below error message: “Fixed disk general POST error”
Cause
By ‘fixed disk’ the error refers to the hard drive, on which the POST test has failed due to hardware reasons. Among various reasons responsible for hard drive failure, some of them are as below:
Read/write head failure: This is the most common reason that causes hard drive crash. Usually, the head floats at few micro meter distance from disk surface, but produces clicking sounds if gets crashed. Hard drive fails to access any data while it is damaged. Motor failure: If the hard drive motor, that actually spins the hard drive platters fails, it causes platters to stop spinning and thus operate anymore. Electronic reasons: If the electronic controller board stops functioning due to electric surges and power spikes, the hard drive fails to get power and fails. Part deterioration: Hard drive fails if any of the internal physical component deteriorates.
Solution
Such POST errors should be dealt by following these steps:
Remove the damaged hard drive from system Install a new hard drive Restore data from backup or consult Hard Drive Data Recovery technicians to recover data. Hard Drive Recovery service is provided by different companies that are equipped with suitable recovery tools, experienced technicians and most importantly, Clean Rooms.
Stellar Information Systems Limited offers industry’s best Hard Drive Data Recovery service. It is offered through Class 100 Clean Rooms. Experts of Stellar can successfully recover lost data in all cases of failure, be it mechanical or electronic. The service is available for all hard disk interfaces including SATA, PATA and SCSI. Stellar has a rich experience of more than 16 years in the field.
Author is researching on the hard drive related problems and explains the situations that can cause data loss .Author has given solution of hard drive recovery and suggested to use hard drive recovery softwarefor lost data recovery.
Article Source: How to Fix Hard Drive POST Error?
The average person who uses a computer on a regular basis doesn’t think about what happens inside a computer once the power is turned on. As long as their version of MS Windows pops up within a few seconds, most people are quite content to continue on with what they want to do on their computer. A computer goes through many processes from the moment the power is turned on before its operating system (ex. Windows, Linux) is fully loaded and takes over.
The operating system is stored on the hard disk of a computer. It is stored on the hard disk because this type of storage is much less expensive and an operating system requires a large amount of storage space. So, in order to make computers more economical, they are designed to use a combination of ROM, DRAM, and hard disks. An explanation of each follows.
Once the power switch is turned on, the “boot-up” process begins. To “boot-up” a computer simply means to start it. Electricity then flows through all of the chips and their circuits. The instructions for what the computer is supposed to do next are found in the Read Only Memory, Basic Input/Output System (ROM BIOS). ROM is memory that can only be read from and has information that is permanently burned into it. It is nonvolatile and will not be lost or disappear once the power is turned off.
ROM BIOS or just BIOS, is designed to begin giving commands as soon as it receives power. The BIOS contains an entire set of instructions, in effect a computer program written into the chip that manages the boot-up process. Without the BIOS, the computer would not know what to do next. The first task that BIOS completes is to make sure that all of the hardware components are working properly (for example: disk drives, external buses, the mouse, the printer). This is called a power-on self-test (POST). After the POST is complete, the BIOS activates other chips on different cards installed in the computer (SCSI and graphics cards) and provides a set of low-level routines that the operating system uses to interface to different hardware devices such as the keyboard, mouse, printer, etc.
Once the POST is complete, the BIOS hands the next stage in the boot-up process over to the central processing unit (CPU). The CPU is a one chip processor or microprocessor that has two distinct capabilities:
1. The CPU carries out all of the mathematical and logical operations including basic math and comparisons of two or more numbers.
2. The CPU has the ability to intelligently manage the flow of instructions and data going into and out of its circuits.
The last instruction that the ROM sends to the CPU is to go to a specific location or address to find its next instruction. An address is a string of numbers that gives directions to where something can be found, much like an address on an envelope. Computers use addresses to keep track of information much the same way as the post office uses them to find residences and businesses. The bigger the number in an address the more locations it can refer to. Most current computers use a 32-bit address space for memory, which means that there can be over four billion separate locations to hold information.
Sometimes the most important aspects of a subject are not immediately obvious. Keep reading to get the complete picture.
The instruction that the ROM BIOS wants the CPU to carry out is sent through a chip on a bus (a set of wires) to the address specified. The data bus is able to carry information into and out of the chip within the CPU. The information is not available within the CPU so it has to look elsewhere. The CPU then sends the address on another bus called an address bus. When the CPU does this, it is called a fetch. The address bus is “fetching” information from elsewhere within the computer. The address bus is only able to carry instructions out of the CPU.
The address bus fetches information from the computer’s memory. Memory is a type of silicon chip that can hold instructions or data. This type of memory can be read from or written to by the CPU, but this type of memory or Dynamic Random Access Memory (DRAM) is volatile. Once the power is turned off, the DRAM looses its memory or information. Since the DRAM is basically a blank slate, the CPU has within, a set of sequential instructions as to where to look for the required information.
Before the address bus can get to memory, it has to pass through a set of chips called a chipset. The chipset refers to a group of chips that provide an intelligent interface for the core components of a computer – CPU, memory, graphics, I/O system, described as core logic or glue logic. If the information that the chipset requires is not in memory, the chipset then sends or redirects it to the Input/Output (I/O) bus. The I/O bus connects the chipset to other places where the information is stored, such as the hard disk. The hard disk allows the CPU to read from it and to write to it. The hard disk is non-volatile so it retains its data or information once the power is turned off. A hard disk is much slower at retrieving data from than memory but memory is much more expensive.
Once the hard disk receives the address (via the I/O bus and chipset), it retrieves the information and sends it back through the chipset and then puts it on the address bus back into the CPU. The chipset functions as a bridge for the two buses; the I/O bus and the address bus.
The CPU uses a four step sequence: fetch, decode, execute, and store. Since the CPU does not retain its memory, it has to obtain its information or fetch the information from elsewhere within the computer. To help with the speed of the process of fetching, the CPU has a pre-fetch area to make the information available more quickly.
Once the information has been fetched, it has to be decoded. Part of the decoding process of the CPU is to decide which circuits are appropriate to use for executing the instructions. Once that decision has been made, the CPU begins to execute the instructions. The part of the CPU where the actual execution of instructions takes place is called the Arithmetic Logical Unit (ALU). The ALU includes groups of transistors, known as logic gates, which are organized to carry out basic mathematical and logical operations. Logic gates are grouped into electrical circuits that execute the CPU’s instructions such as “add” two numbers or “compare” two numbers.
The final step of the CPU is to store the information. This final step takes place after the ALU completes its calculations. The results of the calculations are stored on a chip that has an area called a register. Registers can be accessed more quickly than any other kind of memory but are only for temporary holding (storage) of information.
The CPU also has a clock within it to keep the timing of all of the flow of information and processes of the computer. This clock is vital to the synchronization of all of the processes of the computer. This CPU clock controls all of the operations on its chip. The processes of the CPU can also be interrupted by an external interrupt controller chip which is part of the chipset. The chipset contains a small database of interrupt vector (numerical table). When an interrupt signal comes onto the chip, the CPU saves what it is doing and goes to the interrupt vector to find the address of the instruction that the interrupt is telling it to execute instead. Once it is finished with the interrupt, it goes back to what it was doing. The CPU finds what it was doing in a register called a stack. If interrupts were not possible, the CPU would have to complete one task before it could start another causing the speed to be greatly reduced.
Now that the CPU has found the operating system, loaded it into memory, the operating system takes over and the computer is now ready to be used by its owner. The user can now check email, play a game, or do whatever they wanted to do when they started the computer.
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Article Source: Computer Operations…
When an appropriately configured computer can not access the data, which is stored in the hard drive, the problem could be due to hard drive failure. The hard drive is a primary data storage media that comprises a number of moving components. These components are controlled by the power inputted by the electronic circuitry of hard drive. Among the number of cause of the disk failure, read/write head crash is judged as the most common one. Head crash directly threats the existence of your critical data on disk platters because platter surfaces may get scratched due to head crash. In such situations, Data Recovery New Jersey is required to salvage data from failed hard drive.
In a practical scenario of read/write head failure, when you attempt to boot your computer the hardware checking system POST (Power On Self Test) returns the below given error message:
“1708 Head select error”
You may also encounter this error message during general input or output operations. This message indicates the corruption to one or more than one read/write heads. In such situations, if you do not have proper or current backup of your mission critical data, Data Recovery Service is required.
Read/write head is a critical component of hard drive that is used to read data from and write data to the disk platters. When the disk platters start to rotate, head senses the magnetization of the magnetic material. The head can also modify the magnetization. The head operate at a minor height from hard drive platter surface. Head crash generally occurs due to following reasons:
Damage to the actuator arm on which read/write head is placed.
Dust particles between platter and head.
Accidental dropdown of hard drive
Power outages
Excessive heat inside the drive
Manufacturing defect
In case of head crash and data loss situations, you need to opt for reliable and experienced Data Recovery Service to get your mission critical data back. It is a personalized and sophisticated help that is offered in safe and controlled environment of Clean Rooms.
It is performed by the skilled and trained recovery professionals using advanced tools and techniques. The recovery service experts go through a proprietary process to achieve perfect Data Recovery NJ.
Stellar Data Recovery Inc. delivers recovery service is most of the data loss situations for hard drive, RAID array, NAS, SAN and other storage devices. Service is carried out in Class 100 Clean Rooms by experienced recovery specialists for all hard drives, which have IDE, EIDE, SATA and SCSI interfaces.
Andrew Watson has 6 Years of Experience in the Software Technology field doing research in Stellar Data Recovery Inc. which offers data recovery services , hard drive recovery services,Data Recovery New Jersey.
Article Source: Read/Write Head Errors in Hard Drive and Data Recovery New Jersey
When a computer system is powered up, BIOS (Basic Input/Output System) is the first program (a firmware that is software on hardware) executed by a computer system. The BIOS detects, tests and initializes system devices like hard drives, optical drives, keyboard, display screen etc. After the BIOS check is over, computer system files take control to detect the hardware and software environment. Among all computer storage media, hard disk is the most common one due to its large storage capacity and cost-effectiveness. When the hard drive fails due to hardware issues, BIOS fails to detect it. This generally happens when hard disk suffers physical issues related to one or more of its internals. Attempting to run such failed hard drives can cause more damage to your data. So, if you ever encounter such issues, it is recommended to power down the system immediately and consult data recovery solution providers for recovering lost data.
The first function of BIOS is to run POST (Power-On Self Test) that is stored on a predetermined address in memory. This code is responsible to gather information of all attached drives including hard disk. It makes sure that all hardware is working properly and the minimum hardware required is available. Thus, if the hard drive is damaged, POST may not detect it.
In particular, BIOS may fail to recognize the hard drive post issues as physical crash. But, there can be other issues as well like:
• You have recently changed the BIOS settings and hard disk is not correctly configured.
• Hard disk is inappropriately connected to the system. Power cable or interface cable is damaged or not attached to the mainboard.
• Jumper settings are not correct.
• Hard drive controllers are disabled in BIOS.
To solve the issue, you need to follow these steps:
• Set your BIOS settings to default
• Verify all cables are in good condition and are properly connected
• Check jumper settings. If you have attached two hard drives to a port/connector, make sure that one of them is configured as master and other as slave
• Make sure that all/in-use hard disk controllers are enabled
• If the problem continues, you require a hard drive recovery company that has all the modern facilities and tools to recover lost data.
Data Recovery service incorporates cutting-edge technologies and tools that are intended to recover lost data. When you first send your failed hard drive to a recovery company, the recovery experts scrutinize it under safe and controlled lab environment of Clean Rooms. Based on such analysis, suitable recovery procedures are followed to recover optimum lost data. For example, if your hard disk is damaged due to read/write head crash, experts repair or replace it.
Stellar Information is industry’s leading provider of quality data recovery services. Stellar’s recovery experts work under state-of-the-art Class-100 Clean Rooms. The recovery solutions are available for almost all makes and models of hard drives (SCSI, SATA, EIDE and IDE), USB flash drives and SSDs (Solid State Drives: SATA). Stellar provides complete data recovery solutions for Server, RAID, SAN and NAS hard drives.
K madhav is a data recovery expert and doing research on data recovery software and hard drive recovery.
Article Source: What You Do When BIOS Fails to Detect Hard Drive
During POST or Power On Self Test, computer BIOS attempts to get information regarding all of the devices attached to your computer system. After examining the processor and primary memory (RAM), it checks for the devices like hard drive, CD ROM etc and shows them with messages on screen like ‘Found Primary Master’ and ‘detecting IDE drives’ etc.
-> POST (Power On Self Test) is the first thing done by BIOS when your computer first boots up. POST is an in-built diagnostic program, which examines the hardware of your computer system to make sure that everything is available and working properly.
Many times, the BIOS of your computer just declines to recognize the hard drive, basically makes it unusable- there is no way in which your operating system will recognize the hard drive if BIOS can not. Let’s observe why all this happens.
The most frequent reason of this problem is a badly connected or loose data cable. You should first ensure that data cable is properly plugged in, both into the motherboard as well as the hard drive.
The same thing goes for the power cable, so you should check it as well. You should also make sure that red lines on data cable and the power cable are contiguous to one another.
Once you have ruled out the cable problems, you need to check out the jumper settings on hard drives. If two hard drives are attached to a port, ensure that one is set as masters and other as slave.
Next, ensure that the hard drive controllers on motherboard are not disabled. These hard drive controllers control the IDE devices and without them BIOS could not detect the hard drives.
If any of the above mentioned methods does not work, you need to search for a data recovery expert to cure your hard drive. It seems that hard drive has some internal problems, which can not be cured without opening it. And you are not recommended to open your hard drive at your own.
Data recovery experts are highly qualified and trained professionals, who know all ins and outs of the hard drive and are able to fix most of the physical hard drive problems. To ensure absolute and safe data recovery, always go for the experienced and reliable data recovery company.
Stellar Information Systems Limited is the most trustworthy and leading data Recovery Company, having more than 15 years of rich experience. Stellar’s personalized data recovery services is offered by highly trained data recovery specialists through Class 100 Clean Rooms.
Williamz Jack work as a freelancer and researcher of Data Recovery & File Recovery Software.
Article Source: What to Do When BIOS Does Not Recognize the Hard Drive?
Virus programmers, though disparaging, were few of the most pioneering programmers in industry at some time. They browbeaten the core of operating system and could do magic with MBR and BIOS.
Today’s virus programmers are just some hack script creator. They do not have better understanding of true relations between MBR and BIOS. This term tries to put some light on boot up sequence and the vulnerability we all contribute to.
In last few years, several things in the world of computer have got changed. Now we are using GUI in place of command line. The computers have a high performance, faster speed and high storage capacity.
With all these obviously colossal progresses, the most significant function of the computer has never altered and that is the boot sequence. It might have enhanced, several items have been added but the central point of boot process has not been changed.
The booting process
When you first switch on your computer, the BIOS immediately take over. In the process, it does POST (Power On Self Test). This is a sequence of checks which will examine the hardware resources of your computer.
If POST finds anything wrong, this will consider it as a fatal error and will halt the boot process. It will give you a series of beeps. The BIOS also test the MBR, if it is having some problems, the boot sector will fail and your system will restart again and again.
In this way, you can see the importance of MBR and BIOS of a system for smooth running. If any error occurs in any of these system resources, your system may fail to boot and you may fall in grave situations of data loss.
Both of these system resources are at the stake of corruption due to virus attack and unexpected system shutdown. There are so many computer viruses, which are specifically designed to damage the boot sector of your computer.
If you are among the unfortunate users and face the MBR or BIOS corruption, the resulted data loss may put you out of the business. In such situations, the only thing which can save you and your business is the data recovery.
Data recovery is the way out of extracting your valuable data from inaccessible system. In this particular case, the data recovery could be achieved using the data recovery software.
These are the third party tools, varying from operating system to operating system, which allow users to perform Do It Yourself data recovery in all possible circumstances of data loss. The data recovery software are easily obtainable from Internet.
Stellar Information Systems Ltd is the foremost provider of quality data recovery software. Stellar’s world class data recovery software are available for all computer operating system. Interactive user interface, read only and non destructive conduct, Live Update, and in-depth scanning are some of the major features of these software, which make them first choice of every data loss victim.
Jonny a student of Mass Communication doing research on data recovery and data recovery software. He is also a freelancer for http://www.stellarinfo.com
Article Source: The Black Art of the Data Recovery- MBR, BIOS and Virus
The basic boot sequence for a Cisco router is:
Step 1: The router performs a power-on self-test (POST) to discover and verify the hardware.
Step 2: The router loads and runs bootstrap code from ROM.
Step 3: The router finds the IOS or other software and loads it.
Step 4: The router finds the configuration file and loads it into running config.
All routers attempt all four steps each time that the router is powered on or reloaded. The POST code and functions cannot be changed by the router administrator. The location of the bootstrap code, the IOS to load, and the configuration file can be changed by the administrator-but you almost always use the default location for the bootstrap code (ROM) and for the initial configuration (NVRAM). So, the location of IOS or other software is the only part that typically is changed. Three categories of operating systems can be loaded into the router:
• The full-function IOS image, which is typically located in Flash memory but can also be located on a TFTP server. This is the normal, full-feature IOS used in production; • A limited-function IOS that resides in ROM; and provides basic IP connectivity when Flash memory is faulty and you need IP connectivity to copy a new IOS into Flash memory. This limited-function IOS is called RXBOOT mode.
• A different non-IOS operating system that is also stored in ROM. This operating system, called ROM Monitor (ROMMON) mode, is used for low-level debugging and for password recovery. Unless you are performing password recovery, you would seldom use ROMMON mode.
The configuration register tells the router whether to use a full-featured IOS, ROMMON, RXBOOT mode. The configuration register is a 16-bit software register in the router, and its value is set using the configregister global configuration command. The boot field is the name of the low-order 4 bits of the configuration register. This field can be considered a 4-bit value, represented as a single hexadecimal digit. If the boot field is hex 0, ROMMON is loaded. If the boot field is hex 1, RXBOOT mode is used. For anything else, it loads a full-featured IOS.
Read more about CCNA , CCNA Certification and CCNA Exams
Article Source: Free Cisco CCNA Tutorial