Diagnostic Process

/Diagnostic Process
Diagnostic Process 2017-02-13T15:09:00+00:00


Specific steps to be taken in the diagnostic process for hard drives:

**This is a guideline only and ER Data Recovery Services will not be held
responsible for any loss of data following these procedures. If in doubt,
please email service@erdatarecovery.co.za for more information**

We won’t go deep into specific features of different architectures, but this instruction is
common for all the drives.

Where do most things go wrong? Traditional data recovery is often been done backwards –
that is, starting from the wrong end. We always start with a diagnosis of the drive and repair
if necessary, progresses to disk imaging, and then (and only then) does the actual retrieval
of data begin.

First things first:

  1. It is not recommended to connect it via USB.
  2. Do not test the hard drive in “OS Mode”. When Windows or any other operating
    system starts it can try to use its embedded software tools (i.e check disk) to recover
    the file system. This can have very harmful consequences and can lead the drive
    being completely unrecoverable.
  3. Another possible scenario is when the heads are stuck on platters “sticktion” –
    Usually a “beeping noise” can be heard. This can cause serious damage to the platter
    and destroy essential data.
  4. When a distinct “clicking” noise or any other unusual noises can be detected coming
    from the hard drive.


Here is the checklist of the points we as a DR company need to find out before any data
recovery attempt is made:

  • How and when did the problem appear?
  • What happened with the drive?
  • What has been done to the drive beforehand (software tools used, PCB replacement,
    HDA opened)?
  • Was it in another DR lab or was it assessed by another specialist?
  • What data is essential for the customer to recover (all the data, partition, folder,
    some files)?

  • Does it spin when powered-on?

  • Does it make any unusual sounds (scratching sound, knocks/clicks, beeping, etc.)?

  • Does it give the ID and capacity (correctly or not)?

  • Does it give access to user data?

The next step to take is a visual inspection of the drive. We can divide it into two parts.

HDA and PCB inspection:

  • Check the geometry of the HDA. It can be bent if the drive was dropped (usual for
    2.5″ hard drives).
  • Look at the corners and edges of the drive. There you can find dents or chips on the
    paint that can point that the drive was dropped or hit.
  • Check the screws of the housing and the main label for tool marks to find out if the
    drive was opened before. Some screws of the lid are usually covered by the sticker,
    so if the lid was opened before, you can see that it is damaged or absent. Carefully
    check the top label and see if it is torn off above the screws on top lid.
  • Before powering up the drive always try to shake the drive carefully from side to
    side and listen if there are any moving parts bouncing inside.
  • Powering on the drive in this situation is dangerous, because it may lead to platters
  • In the case when you can hear sounds of bouncing parts inside the drive it is better
    to estimate your skills and ask permission from drive owner for opening the drive’s
    lid and checking hard drive internal parts.

Remove the PCB and inspect it for burnt elements, corrosion, chips on elements, tool
marks, flux/soldering traces, ROM IC (present or not), jumpers position,
SATA/PATA/SAS port condition.
Pay special attention to the HSA (Heads Stack Assembly) connector pads. They often
become oxidized, making the connection not reliable. It is recommended to clean
them gently with soft eraser.

** Never replace the PCB with a donor PCB. The PCB contains more often than not,
adaptive data that is “married” to that specific hard drive. We often get hard drives
for recovery were the PCB has been replaced with a donor PCB. This will, in many
cases lead to the hard drive being unrecoverable **

Now that we have gone though the diagnostic process, we can proceed to either repairing
the hard drive or proceed to the software diagnosis:

As mentioned before: Do not test the hard drive in “OS Mode”. A good and reliable tool to
use for diagnosing a hard drive is MHDD (MHDD 4.5, CDROM iso-image) ~ can be
downloaded here ~.

Please pay close attention to the registers states. This will, more than often, give you a very
good idea of the “state” of the hard drive and will enable you to take necessary and
informative steps further.

Here are three the most typical registers states:

But what does this mean?

When we see DRD and DSC registers on: The drive is ready and waiting for ATA commands
form the computer. In most cases that means we can open a utility and continue

The BSY register is ON permanently: The drive is performing some internal procedure. If the
drive stays in “Busy” state for a prolonged time, it means that there are some Service Area
problems, or Heads problems or PCB problems.

If all registers half-dimmed and the PHY register is not on: There is a connection problem.
Check SATA/PATA cable, check jumper’s position (they should be always set in “Master”

So what happens next?

    1. Check the HDD ID. Is it present? Is it correct? Does it have correct capacity?
    2. Check the common information about the drive (such as Max LBA parameter status,
      S.M.A.R.T. parameters, Write buffer status, and HDD ID details) and read User area

** Please be attentive when performing this test. Don’t leave the drive unattended
for a long time. If the drive has heads or surface problems the test can be too
stressful and lead to serious damage. **

  1. If the drive has started successfully and has access to User area we can scan the
    $MFT (NTFS) and $BITMAP, get the directory listing and do a “targeted” data
  2. Please note that the process for MAC and FAT formatted hard drives are different
    and you will need to have a very good knowledge about FS structures to rebuild
    these File systems.

Other common issues that cannot be resolved without specialized include:

    1. Translator failures: The translator is quite a common failure on Seagate F3.
      The typical sign is readable sectors at the beginning and unreadable sectors at the
    2. A lot of Seagate F3 drives have a problem with LED errors, R/W error problems or
      just stay in a BSY state.
    3. “No HOST FIS-ReadyStatusFlags”or similar type of errors.
    4. “Slow Responding problem” on Western Digital hard drives.
    5. One or more modules in Service Area are damaged.
    6. “On-The-Fly” data encryption specific to WD USB external hard drives.
    7. ROM chip is burnt or have a physical damage.