How to Diagnose and Recover the Most Common Cases

Check on the symptoms your drive is experiencing, see what problems usually cause these symptoms, and find a procedure to diagnose and recover data from drives with a particular problem.

Note: This information won’t allow you to identify problems with 100% certainty, and it doesn’t guarantee that a recommended recovery procedure will work for a specific case. But it will help you understand the most common cases, procedures, and tools used in a professional data recovery process.

  1. Drive won’t spin up.
    1. Failed PCBA board
    2. Corrupted firmware in ROM
    3. Failed heads assembly
    4. Heads stuck to the disk platters
    5. Spindle motor seizure
    6. Failed motor

    Diagnostics: By using the Current Monitoring Add-on for DeepSpar Disk Imager you can diagnose whether the drive has a mechanical issue (d, e), a motor windings failure (f), a power circuitry problem (a), or a failure of other components on the board, such as the microcontroller or the motor controller. DeepSpar Disk Imager 4 also gives you extra diagnostics functionality via SATA Native Functions to help identify a failed board (a), issues with SATA interface, or a corrupted firmware in ROM (b).

    You can use PC-3000 UDMA/SCSI to identify firmware corruption in ROM.

    You can also perform extra diagnostics on the board by finding a compatible donor drive (following the appropriate compatibility rules) and swapping the patient board to a donor to see if the donor spins up.

  2. Drive clicks when powered on.
    1. Bad or degraded heads
    2. Failed board
    3. Corrupted System Area (firmware)
    4. Damaged disk platters

    Diagnostics: You can identify a failed board using one of the methods for drives that won’t spin up.

    You can use PC-3000 UDMA/SCSI to identify corrupted firmware modules in System Area.

  3. Drive is not recognized by the PC, but it spins up and sounds fine.
    1. Corrupted System Area (firmware)
    2. Read instability issues
    3. Failure of one of the read-write heads

    Diagnostics: DeepSpar Disk Imager can identify whether or not the drive has read instability issues.

    A firmware failure in System Area or a failure of one of the heads can be identified by PC-3000 UDMA/SCSI.

  4. Drive is recognized by the PC, but the data cannot be accessed – for example, PC/OS freezes or gives a data access error while accessing the data.
    1. Bad sectors
    2. Read instability issues
    3. Bad or degraded heads

    Diagnostics: All of these problems are easily identified by DeepSpar Disk Imager.

  5. Drive looks fully operational, but some partitions, folders, or files are missing.
    1. Bad sectors
    2. Read instability issues
    3. Corruption of the file system

    Diagnostics: You can use DeepSpar Disk Imager bundled with DeepSpar Recovery Environment to identify all of these problems.

Here are the drive problems mentioned and their recovery procedures.

Failed PCBA board

Problem: This issue could be caused by a burned fuse (or a shorted TVS diode), failure of one of the power converter components, a failed motor controller, or another failed component.
Recovery procedure: Fixed by one of these methods:

  1. Locating and replacing failed components (the easiest fixes are to replace a fuse or remove a shorted TVS diode)
  2. Finding a compatible board from a donor drive, moving the Flash ROM chip (or copying ROM contents using PC-3000 UDMA/SCSI) from the patient board to a donor one, and moving that donor board to the patient drive. Some boards have the Flash ROM embedded into the microcontroller (some microcontrollers have a BGA package) and so copying ROM from the patient board to a donor one or regenerating the ROM based on the Service Area using PC-3000 UDMA/SCSI could be the only option.
Note: Moving Flash ROM from the patient to a donor board is necessary because each drive has a unique set of configuration parameters (called adaptives) burned into ROM. These adaptives are used to optimize the drive’s performance and they are compiled by the vendor for each drive during the manufacturing process.

Corrupted firmware in ROM

Problem: The contents of ROM get corrupted.
Recovery procedure: Repair ROM contents by using PC-3000 UDMA/SCSI. A firmware library for the specific drive family is usually required to restore ROM.

Failed heads assembly

Problem: The heads assembly has either physical or electrical failure. In some cases it is a failure of a preamplifier selector chip mounted on the heads assembly.
Recovery procedure: Swapping heads assembly from a compatible donor drive in a cleanroom environment using various specialized tools, such as Head Combs. After a head swap, the drive will frequently experience read instability issues.

Heads stuck to the disk platters

Problem: The heads usually stick to the disk platters when the drive is powered off and, due to some unexpected processes, there isn’t enough time for the heads to move back to the parking zone before the platters stop spinning.
Recovery procedure: Fixed by opening the head disk assembly in a cleanroom environment and manually moving the heads assembly back to the parking zone. In some cases, this issue results in read instability problems or failed heads assembly.

Spindle motor seizure or a failed motor

Problem: The motor bearing is jammed for various reasons, which prevents the drive spindle from spinning, or a motor windings failure.
Recovery procedure: In some cases it is possible to unlock the motor bearing. However, in most cases the entire disk assembly needs to be swapped to a compatible donor drive. This is usually the most difficult cleanroom operation. Many data recovery companies prefer building platter swap tools themselves to adapt them to their own swap procedures, since commercially available tools have many limitations and usually work well only on certain drive families.

Bad or degraded heads

Problem: Physical or electrical issues with one or more heads of the heads assembly cause a partial or complete loss of access to data.
Recovery procedure: If the drive starts clicking right after it is powered on, you need to identify and disable the bad/degraded heads in the drive’s RAM by using PC-3000 UDMA/SCSI. If just one or two bad heads are identified, imaging can be processed on the good heads using DeepSpar Disk Imager or Data Extractor, so user data that is located on the good heads is recovered. If too many heads are bad or the entire heads assembly is failed, a heads swap from a donor drive is required.
If the drive doesn’t make an indefinite clicking sound and identifies properly, you can use DeepSpar Disk Imager to locate the bad/degraded heads, image good heads first, and then try imaging degraded heads.

Damaged disk platters

Problem: Physical issues exist, such as a scratch on the disk surface, with one or more disk platters usually causing a complete loss of access to data.
Recovery procedure: In most cases drives with damaged platters are unrecoverable, because of the fact that such damage leads to an almost immediate failure of the heads assembly, so even if a head swap is performed transplanted heads will fail after the swap.

Corrupted System Area (firmware)

Problem: System Area is an area located on the negative cylinders of the disk platters. It contains up to several hundred firmware modules organized into the HDD firmware system. If some of the critical firmware modules become corrupted, the drive cannot initialize properly which results in either an incorrect operation with limited access to data or a complete loss of data access.
Recovery procedure: Firmware modules can usually be repaired by using PC-3000 UDMA/SCSI and a firmware library for a corresponding drive family. Since some modules are unique to the drive, such as modules of adaptives or the translator subsystem, corruption of certain modules may lead to an unrecoverable case.

Read instability issues

Problem: Various erratic abnormal behavior of a dying drive, such as a drive that occasionally becomes unresponsive, responds very slowly, makes occasional clicks while executing certain commands, has a failure of one of its non-critical subsystems (such as SMART) causing the host to abort, or has other degradation factors.
Recovery procedure: Use DeepSpar Disk Imager to handle all those instabilities. The imaging process may need to be adjusted to automatically handle particular drive problems. You may need to make one of these adjustments:

  • - Preconfigure the drive for lighter operation (for instance, switch off the SMART subsystem and the read look-ahead feature)
  • - Use various types of drive reset commands or automatically repower the drive to abort its abnormal operations in a timely manner and continue imaging
  • - Customize the imaging algorithm with Event-Action definitions addressing particular problems of the drive
  • - Use different read commands
The more features your imaging tool has, the better you can handle certain drive instabilities to avoid repairing the drive for data recovery purposes.

Bad sectors

Problem: Problematic areas exist on the disk that cannot be read at all or contain corrupted data. There are many causes of bad sectors, including degraded heads or platters, corruption of a sector’s ECC data, problems within the read-write channel, and even firmware corruption.
Recovery procedure: Use DeepSpar Disk Imager to try retrieving data from bad sectors using either Read Ignoring ECC commands or accessing data via the drive’s buffer. The drive provides a particular error in its ATA Registers with each bad sector it hits during imaging. This behavior helps diagnose the cause of the bad sector. It is important that the imaging tool provides access to that error and also gives the ability to specify a particular action to be executed for each particular sector error.

Corruption of the file system

Problem: One or more partitions on the drive are corrupted, which prevents the operating system from accessing the files/folders located on the partition.
Recovery procedure: File system recovery can be performed using DeepSpar Recovery Environment or Data Extractor.