How To Recover Data From A Faulty Hard Drive: Risks and Rewards

Hard Drive Connected to A Makeshift Computer

Hard Drive Connected to A Makeshift Computer

Hard drive recovery can be equally easy and difficult depending from what perspective you look at it or what level of technical expertise you possess. Most people will not have any experience or even knowledge of how hard drives work and how to deal with them when they fail. Even most IT technicians and computer specialists will not have the right level of expertise or the right equipment to deal with a data loss situation as a result of a hard drive failure unless they have been trained for it or or have a good knowledge of data storage systems and possess the right equipment and the right environment in which they can salvage data from a failed hard drive.

To understand the issues related to hard drive failure and how best to deal with them, first we need to know how data is stored in hard drives without getting too technical. All computer systems rely on data storage in one way or another as they are primarily data processing and data storage systems. Computers are input, storage, output systems in principal in which the data storage is the critical bit in all its operations. When you store a file in your computer, you input your instructions by clicking on the “Save” button which is translated into digital bytes holding the data (i.e image, document, music, video etc) and placed in the registers of logical sectors of the data storage device (i.e a memory stick, hard drive, memory card or external disk).

Now if for some technical failure the flow of data is cut off or the data is not saved for whatever reason, the files, images and documents will be lost. Let’s start with data loss as a result of loss of power or system crash. If your computer crashes or loses power in the middle of the “save” operation, the data on the destination media might be corrupted or unusable because the format has not been saved with all its constituents components which make up a usable file. Therefore when you recover from the crash and attempt to read that file, it will not open or it will show garbage instead.

Data Loss As A Result of Partition Corruption (HDD Logical Failure)

How data is saved on hard drive tracks

How a hard drive becomes filled with data. As more and more data is added or altered, free contiguous sectors become harder to find. The result is that pieces of files are scattered all over the hard drive.

Another cause of data loss is partition corruption or damage. This is different from physical damage to the hard drive which we will address later on.  In order for all data to be saved on disk, first it has to be formatted so that it can “save” and hold the data. Basically by formatting the hard disk, you create a “data container” which holds the data. Just imagine that data is like water. Water is fluid and unless it contained in a glass or a jar, you can’t see it or use it and it will spill and cannot be seen. The same is true about data. Every operating system such as Windows, MacOS, Linux or Unix have their own file systems.  In order to save data, the OS needs to format the media thereby creating a file system so that the data is contained and can be visible through the eyes of the operating system which runs your computer. Therefore file systems such as NTFS, FAT32, ExFAT, HFS, HFS +, Ext2/Ext3, UFS, ReiserFS, EFS, ReFS have been created so that different types of data storage systems can be formatted to save and hold data. Every file system has its own cataloguing and journalling system by which it records all the saves and deletions and history of the files. If the catalogue file or journalling in the file system becomes corrupted as a result of power cut, power surge, bad sectors, degraded media or bad read/write heads, data loss will occur and therefore the data storage device namely the hard drive or memory stick, will become inaccessible and dysfunctional.

Data Loss as a Result of Electronic Failure (HDD Electronic Failure)

Fried Chips on Hard Drive Logic Board or PCB

Fried Chips on Hard Drive Logic Board or PCB

When a hard drive, memory stick or external disk develops an electronic fault, communication between the computer OS and the data storage device is lost and therefore the flow of data to the media is cut off. A typical hard drive has an Printed Circuit Board (PCB) or Logic Board which is basically an electronic circuit consisting of a main Central Processing Unit (CPU) responsible for controlling and managing the flow of data to and from the computer and few other chips for controlling the motor and read/write heads as well as memory modules for caching (temporary data storage) and SMART (Self Monitoring And Reporting Technology) which stores read/write errors and keeps track of the hard disk health. A hard disk PCB can fail as a result of a power surge, unstable power, electrostatic discharge or wrong voltage or polarity and thereby frying the chips and diodes on board. (See figure for fried chips.) This leads to electronic fault and the hard disk becomes completely inaccessible and data is lost. This also may also cause partition or file system corruption as flow of data is suddenly disrupted and cache data on it way to be saved on the hard drive fails to reach the media. It is never a good idea to swap over the faulty PCB in a hard drive with another disk with the same size and the sames specs. On the face of it, this appears to be a great idea but in practice it may turn out to be the worst thing you can ever do to damage the hard drive. You might think that your hard disk will start spinning and you can gain access to your data. This does NOT work in 99.9% of the cases as each PCB has been specifically programmed to be used with that particular disk. The PCB holds special information about the drive model, serial number and the location of the storage areas on the data platters. More crucially, over the drive’s lifetime, individual sectors on the hard drive become unreadable or unusable. The internal error control system of the hard disk will reallocate the bad sectors with new good sectors from a limited bank of spare sectors. The firmware stored on the PCB, keeps a map of all these space re-allocations and this map is specific to the faulty hard drive. If you replace a faulty PCB with a good one from a perfectly matching hard disk, it will not only work but will cause the hard disk to click and you will potentially damage the read/write heads of the disk and scratch the surface of the platters on which the data is stored, thereby rendering the hard disk irrecoverable even if you use the professional services of a highly skilled data recovery company.

Data Loss as a Result of Physical Hard Drive Failure (HDD Mechanical Failure)

Physical failure of a hard drive leading to data loss can be more serious and data recovery from mechanically faulty hard disk much more challenging. Quite often user drop their laptop or the external hard drive and as a result of the shock sustained to the read/write heads and the motor, the hard drive starts clicking or clunking or starts making other funny noises. The impact can be even more magnified if the hard disk or the laptop had been operational and spinning at the time of the drop. Even if you flip your external hard drive on the disk while it is on, it may be seriously damaged. Sometimes the hard drive breaks down or starting clicking after a few days or weeks or months of the fatal drop as any shop to the the hard drive will definitely have either an immediate or delayed failure. So if you are lucky and your hard drive is still accessible after the drop, back your critical data first and immediately. However if you hear any clicking or unusual noise and the disk is not recognised by your computer or prompts you to format it, STOP! Just power down the laptop, unplug the hard drive and seek professional from an experience data recovery company. Don NOT be tempted to open the hard drive to see if you can repair it or can get it going as there is nothing you can do. A physically faulty hard drive must be handled by a highly skilled and professional data recovery technician in a controlled environment using special tools so that it is temporarily repaired using 1 or more donor hard drives so that it can be successfully imaged and a healthy virtual clone of the faulty hard drive can be created. Once the clone is created, the data recovery specialist may still have to do some more work to do as the file system or system track or catalogue file may be missing or faulty and he may need to do some extensive manual work to repair the virtual image prior to recovering the data fully. Beware! DIY does NOT work in hard drives suffering from electro-mechanical failures. I am pretty sure you do not want to perform heart surgery with the kitchen knife on the coffee table!

I have Lost Data! What Can I do?

I have Lost Data! What To Do?

If you have lost critical data, seek professional help. DIY hard drive recovery may make matters much worse.

If you in the unfortunate situation of losing data as a result of partition corruption or hard drive electro-mechanical failure, do NOT panic! Keep cool and stay calm and stop doing silly things such as bashing the hard drive, freezing it or taking off the top of the hard drive to expose the read/write heads and the platters! You can and you will damage your hard drive even further and render the task of a hard drive recovery professional much more difficult and more costly. Just turn off your computer and power down your external hard drive. Pick up the phone and consult a data recovery professional. He will be able to guide you through whole process of data recovery analysis, quotation and service delivery leading to a successful hard drive recovery so that you get all your data back contained in a new healthy hard disk. Obviously once you have your data back, you will promise to make redundant copies of your data and ensure you have proper backup system in place.

Call a data recovery professional by dialling 0203 633 2081 now. If you need an emergency data recovery service, call or text 075 380 71627 NOW.

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