Imagine this: you're busy working on your computer and need to access documents saved on your external hard drive. You connect it, get ready to find your data, and...nothing happens. Your hard drive isn't working. Uh oh. Before you panic, there are several things you can try on your own before calling in the pros.
Data loss can be due to a number of factors, but two are the most common. The first (and easiest to resolve) is software related. You've accidentally deleted an important folder and emptied the recycle bin, or gone and formatted the wrong drive by mistake. The second—and probably most common—cause of data loss is a fault with the hard drive itself. Given the complexity of modern drives it's no wonder that somewhere along the line something will go wrong. When the drive suffers from some form of failure there's often little that you can do yourself to get the data back—professional data recovery services are usually required. However,there are certain failures that you can attempt to resolve yourself.

Recover Your Data with Software

When dealing with a software data loss, the first and most important thing to keep in mind isnot to work with the drive in question. Every second that the drive is connected to a running system is a second that you lose your chances at recovery. Your operating system is reading and writing to your drive constantly, whether you're actively doing something or not. Now that your system is seeing the deleted data as ‘free space' it will happily overwrite this area—along with your chances of recovery.
  1. Shutdown the machine connected to the drive you've deleted data from. Now that your drive is ‘safe' you can make a clone of the drive and attempt the recovery from the clone. There are a number of ways to clone the drive, some easier and quicker than others.
  2. Scan the clone with a few different recovery programs. There are numerous options here, both free and paid-for packages are available. Recuva is a good free option, while Zero Assumption Recovery works well if you want to splash out a few dollars.
How to Recover Data When Your Hard Drive Goes Belly Up

Pictured: The basic components of a hard drive with top cover off and PCB removed.

Recover Your Data with Hardware

Having covered the ‘deleted data' section of data recovery is all good and well, but what happens if your drive is not even being detected by your machine? Or your machine can see the drive, but just hangs when you try to access it? What about if the drive is completely dead and won't even spin up? Let's briefly cover the main components of a drive, see which components can fail, and what symptoms each failure might exhibit.
PCB: This is the (often green) circuit board attached to the bottom of your drive. It houses the main controller (the equivalent of your computer's CPU) along with many other electronic controllers. This is the interface that turns your 0s and 1s from the platter into usable data that your computer can understand.
Platters: Your drive contains one or more thin, circular platters. These spin around at anywhere between 5,900rpm to 7,200rpm on consumer drives and are the media that actually store your data. Made of glass or some form of alloy and coated with a magnetic layer, they can store anything up to 4TB of data.
Head assembly: Data from your drives' platters is read by means of a series of read and write heads. While in operation, these heads are not actually in contact with the surface of the platters. In fact, they ‘fly' nanometers above the surface of the disk, reading and writing data. Typically a drive will have 2 heads per platter, so a large capacity drive with 3 platters will be paired up with 6 heads, one for each side of each platter. If these heads fail physically or the drive is dropped or knocked over, the drive can experience a ‘head crash' where the heads no longer fly over the platters, but instead make contact with the surface and destroy your data at a few thousand revolutions per minute.
Firmware: Your drive runs its own mini operating system in order to deal with all of the data and operations required to access it. Most of this firmware is stored on the platters. A small portion is stored on the PCB, which is required when the drive starts up. Firmware can go wrong, leading to inaccessibility of your data. Unfortunately hard drive firmware is not similar to your mobile phone or tablet—you cannot just update or reflash it. Each drive has its own unique modules and parameters and is highly complex in nature.
Now that we understand the basic components of a hard drive let's look at some common failures and symptoms you might experience, determine which component could be causing the problem, and see if we can tackle some of these problems DIY style.

If Your Drive Isn't Spinning Up At All

This is the one instance where you have a relatively good chance of resurrecting your drive if you're prepared to put in some time and effort. If the drive does absolutely nothing when you apply power to it (no noises at all), it is 99% a PCB problem. With older drives, you could sometimes find a matching PCB from another matching drive, swap it over, and voila. However, on new drives, technology and architecture have changed and each drive contains microcode unique to the drive it's attached to. Simply swapping the PCB with a matching, working equivalent has almost no chance of working and can be outright dangerous to your data.
There are two main causes of failure here, either a TVS diode (fuse) has shorted due to overvoltage, or a vital component on the PCB has failed. Hard drive PCBs often have two TVS diodes which act as fuses to protect your drive in the event of a power spike. There will most likely be two of these: one for the 5v and one for the 12v rail. If you accidentally plugged in the wrong power adapter to your external drive, or you experienced a power surge, a TVS diode might have sacrificed itself. If the shorted TVS diode is the only casualty and the rest of the PCB components are OK, then simply removing the shorted diode is enough to bring the drive back to life.
You can test this with a multimeter—if the diode reads zero ohms, or close to it, then it has indeed shortened. When shorted these diodes often have a noticeable burnt smell and might have visible burn damage. Note that when a TVS diode is removed the drive is no longer protected, so ensure that the power supply you connect to the drive is correct and healthy.
How to Recover Data When Your Hard Drive Goes Belly UpPictured: A PCB with the TVS diodes highlighted
If the TVS diodes don't smell burnt and show the correct digits when measuring them, then the problem is the PCB itself. A replacement PCB is required, but not just a straight swap. There is an 8 pin ROM chip on most PCBs that contains unique firmware info that is required to start up the drive. This needs to be moved from the old PCB to the new in order for the replacement to work. Some hard drives, especially Western Digitals, do not have this 8 pin chip—the firmware is stored in the main controller which is virtually impossible to move.
If you want to replace the PCB then you'll need to fine a matching replacement and have the ROM chip moved. There are many online providers that will sell you a matching PCB. Some of them even offer to move the ROM chip for you, saving you the hassle of soldering and possibly damaging the chip. If the PCB was the only damaged component and the drive's internals are OK, then after the replacement and ROM swap, your drive should be up and running again. Another PCB-related item to check are the head contacts. Sometimes they corrode with time, but are easily cleaned with a rubber eraser.
How to Recover Data When Your Hard Drive Goes Belly UpPictured: The contacts on a PCB can cause problems when they become tarnished like this.

If Your Drive Is Spinning Up and Making Clicking Noises

This is a serious failure and indicates a failed head or heads. It could also mean that your drive has suffered from platter damage if a head crash has occurred. Either way, this is a job for the pros. The drive will need to be opened in a clean room environment in a lab and a replacement head assembly fitted in order to try and recover your data. If your drive is clicking, it's best power it off and leave it in this state until you can send it to a professional recovery company. Powering it up in this state could degrade the disk further, to the extent that it's no longer recoverable.
How to Recover Data When Your Hard Drive Goes Belly UpPictured: A hard drive that experienced a head crash and made a deep scratch. This can render a drive unrecoverable.

If Your Drives Spins Ups and Is Detected by Your Computer, But Hangs When You Try to Access It

This usually means that the magnetic media is degraded. Basically, there are a large amount of bad sectors that the drive is trying to read, failing to do so, and hanging. This is a common problem that occurs over time and can be worked around, but only with professional data recovery equipment, more specifically a hard imager. If you look at the SMART values of the drive you'll notice and large amount of reallocated sectors to confirm your suspicions. If the data is important then send it off to the pros.
If you want to have a crack at it yourself (and risk making the problem worse or losing your data altogether) then you can try a software imager that can work around bad areas. Seeing that software commands ultimately goes through the BIOS, the effectiveness is limited. The best option if you want to go this route is a free Linux application called dd_rescue. It can skip bad areas and image in reverse.

If Your Drive Makes a Beeping Sound When You Power it Up

The beeping sounds you are hearing is the motor trying to spin the drive up and failing to do so. This is caused by one of two things, both serious mechanical failures. The most common is what's known as stiction. The heads of your drive park either in the center or on a ramp at the edge of the drive when not in use. Remember, the heads don't make contact with the data area of the platters, they fly just above. Sometimes, the heads can fail to park properly and the platters stop spinning with the heads still over the data area. Because of the extremely smooth surfaces of both the platters and heads, they literally stick to each other, hence the name stiction. The drive needs to be opened up in the lab, heads carefully removed and most likely replaced, definitely not a DIY job.
How to Recover Data When Your Hard Drive Goes Belly UpPictured: The head assembly with drive turned off and heads in the parked position. With stiction, they would be stuck somewhere on the platters.
The other cause could be seizure of the motor spindle. This is the spindle around which the platters rotate. It can become seized if the drive suffers a hard knock or drop. It's not a particularly common fault, except for Seagate drives as they have a particularly fragile spindle. There are two ways for this problem to be resolved, both of which require pro intervention. Either the spindle can be replaced or the platters are moved to a new hard drive casing along with heads, PCB, the works.

If Your Drive Sounds Normal but is Not Detected, or is Detected as the Wrong Capacity

This normally indicates a problem with some area of the firmware. Either it's not being read properly which could actually be head problem, or there is some corruption that needs to be resolved. A few years back there was a well-known bug with Seagate 7200.11 drives with firmware version SD15 known was the BSY bug. Googling this provide a wealth of info of the huge amount of failures were caused by this firmware glitch. There was a DIY solution for this particular problem, but with today's drives there is nothing that the end user can do but to send your drive in for professional help.
So, there are a few instances where you can attempt to recover your own data. If you've accidentally deleted your data then you might be in luck. If the drive is completely dead and won't even power up then you could go the DIY PCB route if you wish to tinker. Other than that, if your drive is making unusual noises or acting in a peculiar manner, you'll need to hand it over—together with some hard earned cash—to a data recovery professional. Remember,ANY attempts at data recovery are risky. If the data is important, take it directly to the professionals.
Nick Parsons is the Founder of SouthBit Data Recovery, leading data recovery service provider in South Africa. He founded SouthBit after receiving his honors degree in digital forensics. SouthBit Data Recovery rovides recovery services to all media including hard drives, SSD drives, and RAIDs. People can get more info on how their hard drive works by viewing their site at here.

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 http://www.etechies.in/etechies-rohitchaudhary-siddharthBhatia-samarthgoyal.html

Launched in April 2010, “eTechies.in” started with a simple idea of offering users in India with dependable Technical Support and Quality Repair Service, backed by a knowledgeable & certified team of resources; serving online and at the doorstep.
Our first few hires were developers and UI resources to help us build a proprietary all-in-one platform enabling and delivering customized solutions to all our users. This was soon followed-up by other technical resources. In no time, we were growing at a fast pace. The strong validation of our service model is via our referral channel of customer acquisition. We do believe that a happy customer talks. Thanks to our customers’ frank feedback and criticism, we continue to accept and make eTechies.in service even more user friendly.
We as a team strongly believe in the value creation philosophy and hence imbibed "CREATE" (Customer First, Result Oriented, Execution,Achievement & Contribution, Trust & Integrity, Excellence & Quality), as our core value set that drives all our executive and operational decisions. The CREATE philosophy drives our unified vision of setting-up “etechies.in” to be the “Most Preferred Service Provider” and a “Category Leader” in the chosen business domain. We work across diverse geographical, cultural and language divides to seamlessly deliver quality services to all our users consistently each and every time.
We believe that good things happen to good people. So it was only obvious, when Industry leaders came on-board and aligned as force multipliers with “eTechies.in’s” mission to create and set-up a business that follows consistent profitable growth over a period of time. Rajan Anandan, like a true angel, joined hands in Oct 2010. The legendary Kanwal Rekhi, John Dougery Jr., Samir kumar and Parag Dhol from Inventus Capital Partners did the honours by accomplishing a successful Series (A) Institutional infusion of US $ 2 million in December 2011.
We continue to grow and thank our ever-increasing users for their candid opinions and appreciations that helps us be better by the minute.
We hope to serve you with pleasure soon.

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http://lists.econsultant.com/top-10-hard-drive-data-recovery-services.html

Top 10 Hard Drive Recovery Services


Recover your data from failing hard drives. Call these services.

If your hard drive makes noises, is unable to read data or you need to recover your valuable data,
shut down the computer, remove the hard drive, and call any of these data recovery services.
  1. Secure Data Recovery Services : 800-388-1266
  2. Salvage Data Recovery Service : 800-970-7188
  3. ADR Data Recovery : 800-450-9282
  4. DTI Data : 866-438-6932
  5. Disk Doctors : 800-347-5377
  6. DriveSavers Data Recovery : 800-440-1904
  7. Eco Data Recovery : 800-339-3412
  8. Gillware Inc. Data Recovery : 877-624-7206
  9. InterData Recovery Services, Inc. : 800-709-0326
  10. Midwest Data Recovery : 866-786-2595

A few more Hard Drive Recovery Services


  1. Optimum Data Recovery : 800-580-4959
  2. Stellar Information Systems : 866-978-0600  (Has India Office Also )
  3. Vioplex Data Recovery Services : 888-254-5823
  4. WeRecoverData : 866-400-DATA
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 http://campusflava.blogspot.in/2013/05/how-to-choose-data-recovery-company.html

How to Choose a Data Recovery Company

"Data Recovery" is a dreaded term referring to the restoration or retrieval of files on a portable mass storage device that is no longer functioning properly.  Fortunately, there is an entire industry devoted to this all-too-common problem.  Whether its a USB flash drive, SD card, XD card, SSD drive, or hard drive, this guide will help put you on the right track to find you the right data recovery company for the job.  For this article, we will be using a defective USB flash drive as the example. The steps below begin with the initial failure of the drive, and end with the successful recovery of all files it contained.

Steps

    1
    Don't panic. It can be horrifying upon realizing that you can suddenly no longer access all the files contained in your drive, but furiously unplugging/replugging it in the computer only risks further damage.
    2
    To ensure it is in fact the flash drive that is malfunctioning, plug it in to 1 or 2 other computers available to you.  If a friend or co-worker isn't available, find a public computer at a library for example. Again, you need only plug it in one time to see if it's working or not. Alternatively, you can try using a free data recovery software program; if the program does not recognize the device, internal damage can be confirmed.
    3
    If you receive the error message: "USB device not recognized" -or- "This device needs to be formatted"  see this WikiHow Article.  If not, continue to the next step.
    4
    Assuming the data stored on your device has any importance at all, it's time to begin searching to enlist the services of a professional data recovery company.  In this case, a search for "USB Data Recovery" will provide adequate options.
    5
    Begin at the top of the list of search results online.
    6
    When looking at a data recovery company website, look for indications of their credibility.  Just because a company has a flashy website doesn't mean they do quality work; look for testimonials, reviews, or any indication that they have done business with a large corporation or federal agency
    7
    Next, find the companies' pricing page.  Data recovery is not a 'one size fits all' industry, and therefore should be priced accordingly; avoid companies that offer flat rate pricing.  Also, you wouldn't go to a restaurant and pay before you eat, and the same goes for data recovery; the company you choose must have a 'zero costs until successful recovery' type of policy.  Note: The only exception to this is a small shipping and diagnostic fee that will likely need to be included when you ship your device to them.
    8
    When you are satisfied you have found a reputable and cost effective company, find and fill out a service order form located on their website.  Pack up your device in a padded or bubble-wrap envelope and ship it to the company address. Note: NEVER use a standard paper envelope to ship your device; it will likely get damaged or slip out of a tear in the paper.
    9
    Be patient.  Some companies offer live tracking services so that you can see the status of your order without having to call in and ask.  If you haven't gotten an update after 5 business days, call in or check your e-mail for any new information.  Cross your fingers for a success!
    10
    If the company was successful in recovering your data, they will contact you, and usually by default they will ship a data CD or DVD containing your files. Hooray!  It is worth noting that some companies offer additional services such as an upload link, which allows you to download your recovered files immediately after a success from an online link provided by the company.

Tips

    When looking for information pertaining to the quality of work  and credibility of a data recovery company, try doing a quick Google search of, " reviews" and see what past customers have said about them.
    If you know for a fact that your device is suffering from moderate to high physical damage, contact your prospective companies and ask them if they have the tools and experience to do "NAND level recoveries."  If they say yes, this means that they can recover your data as long as the memory chip on your device is intact; even if everything else is destroyed.
    Most portable storage devices on the market today use NAND flash as a means of memory storage.  If the outer casing of your device is removed, look for 1 or more large black rectangular-shaped microchips with silver "legs" on each end.  If these chips are intact, a company with NAND recovery capabilities can still recover your data. Alternatively, if these chips are cracked or broken, your files are almost certainly gone forever.

Warnings

    Trying to repair physical damage inflicted on your storage device by yourself can cause further damage  and is strongly discouraged.
    Research prospective companies thoroughly before sending them anything; there are several data recovery scam operations.

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http://techmuck.blogspot.in/2012/03/data-recovery-with-gnu-ddrescue.html


Disclaimer: This article is intended for those of you technically inclined enough to even attempt data recovery. This involves (minimally) being able to burn a CD, use command-line utilities, and some hardware knowledge.

Things to Know

If your hard drive is dying (i.e. making weird clicky noises, giving read errors, etc) MAKE A CLONE COPY OF IT ASAP. The more you use your dying drive, the greater the likelihood of more errors developing. Copy your data onto a different (not dying) drive and then stop using the bad drive. Always perform data recovery techniques on a copy of the original drive. If one of the data recovery techniques fails, it may further scramble your data. Work from a copy. I can't emphasize that enough.

Linux has a very handy tool called ddrescue which can make a clone copy of a disk. It also offers the option to keep retrying to read the bad areas after the first pass, in hopes that maybe it'll work on the 2nd, 3rd, 4th try, etc.

Things You Will Need
  • Your bad hard drive.
  • A working hard drive which has at least as much storage as your bad hard drive.
  • A way to burn yourself a copy of  System Rescue CD (or any other Linux Live CD which includes ddrescue)
  • A computer with both (bad and good) drives connected to it.
The Procedure
  1. Boot the computer with the System Rescue CD.
  2. At the root# prompt type fdisk -l to list all the attached drives.
  3. Assuming we're dealing with 2 modern SATA hard disks, likely one will be listed as /dev/sda and one will be listed as /dev/sdb (this may vary depending on your configuration)

    For the purpose of this article, we shall say /dev/sda is the bad drive and /dev/sdb is the working drive.
  4. Clone sda to sdb with ddrescue:

    root# ddrescue -r-1 -n -S -v /dev/sda /dev/sdb recovery.log
  5. Here's a breakdown of what the command actually does:
    1. -r-1 = retry the damaged areas infinite times
    2. -n = Skip the splitting pass. Avoids spending a lot of time trying to rescue the most difficult parts of the file.
    3. -S = Sparse mode. May save a lot of disk space in some cases.
    4. -v = Verbose mode. Shows all the details about what's happening.
    5. /dev/sda = the source drive
    6. /dev/sdb = the destination drive
    7. recovery.log = The name of the log file. (can be whatever name you want.) In case you need to stop and restart the process, the log file will keep the spot of where the process left off.
  6. This process can be very slow. Depending on the size of your drive and how badly it's performing, it can take days. However, if your data is really that important, it's worth it. Patience is key.
  7. Once the drive finishes it's initial pass of copying the good parts of the drive, it will continue to retry the areas which had errors. Typically by about 4+ passes of the bad areas, it's pretty much certain you're not going to get any more information from those areas of the drive. Cancel the ddrescue process via CTRL-C. Store the damaged drive in a static bag. Don't do anything more with it in case you need to clone it again.
  8. Hook up the drive with the copy of the bad disk as a secondary drive on a working computer. See if you can access the data. There's a number of applications available which will attempt to repair the drive if it's still unreadable. (Perhaps the File Allocation Table needs to be rebuilt.)
Here is a pretty good list of data recovery software you may want to try on your cloned disk.
    Just remember don't run data recovery software on the original drive. It may cause further damage to the disk and render your data completely unrecoverable. Always work from a copy.

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