Assessing the Damage
When an external hard drive suffers physical damage, the first step is to assess the type and extent of the damage. This will determine the best approach for attempting to recover data from the drive.
Some types of physical damage include:
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Dropped drive: If the drive is dropped, especially while powered on and the heads are in motion, the impact can cause the read/write heads to crash into the platter and damage the surface. This often results in scratches or gouges on the platter surface that corrupt data.
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Water damage: If the drive gets wet, water can cause corrosion of the electrical components as well as damage to platter surfaces.
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Fire/heat damage: Excessive heat can melt the drive casing and warp or melt the platters and internal components. Soot and ash can also contaminate the drive surfaces.
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Crushed/bent chassis: If the external drive chassis is bent or crushed, this can misalign the spindle motor and prevent the platters from spinning properly. It can also misalign or damage the read/write heads.
Inspect the external case for any cracks or damage points. Open the case carefully to examine the internal components. Look for scratches, corrosion, soot contamination, warped/melted platters, and bent spindle motors. The more severe the physical damage, the lower the chances of recovering data intact.
Recovery Options
The approach to recovering data depends on the type of damage sustained:
1. Logical Recovery for Light Damage
If the drive powers on and the platters spin normally, the damage may be limited to logical corruption of the file system rather than physical damage to the platters. In these cases, data recovery software can often read sectors of the drive and reconstruct files. Examples of logical damage include:
- File system corruption from an improper shutdown during write activity
- Reformatting/repartitioning the drive
- Accidental file deletion
Data recovery software scans the drive sectors looking for file signatures to reconstruct files. Two popular data recovery tools are SpinRite and Ontrack EasyRecovery. Use the software to attempt extracting files from the damaged drive and copying them to another healthy drive.
2. Repairing the Drive
If the physical damage prevents the drive from spinning up or being detected by a computer, more invasive repairs may allow data recovery.
Head/platter damage – A skilled technician can open the drive in a dust-free clean room and replace damaged read/write heads or platters. This requires specialized tools to open the drive casing and precisely reassemble the drive after replacing the damaged components.
Motor damage – The spindle motor can sometimes be repaired or replaced to get the platters spinning again. Again this requires delicately opening the drive in a clean room.
Once hardware repairs get the drive powered on and platters spinning, logical recovery software can be used to extract files from the repaired drive.
3. Disk Imaging and Data Extraction
For more severe physical damage like crushed platters or melted components, accessing the drive directly may be impossible.
In these cases, a final resort is to ship the drive to a professional data recovery company like DriveSavers or Kroll Ontrack. They have specialized equipment to image damaged drives.
Drive imaging copies the raw magnetic data pattern recorded on the platter surfaces without needing to access the drive logically. The image is stored digitally as an “image file”. This preserves the drive contents before any further physical degradation occurs.
Recovery experts then use this raw image file to reconstruct files using sophisticated recovery algorithms. This has the best chance of recovering data despite severe physical drive damage. However, costs often run $1000 or higher for professional recovery from extreme drive damage.
Preventing Physical Drive Damage
To avoid the challenges of physical data recovery, some best practices include:
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Use quality external drive enclosures with rubber bumpers/internal shock mounts. Avoid thin lightweight enclosures prone to damage.
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Keep the drive on a stable surface and avoid moving it when powered on.
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Only connect/disconnect the USB when the drive is unmounted and powered off.
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Store drives in a cool dry location and avoid water sources.
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Consider redundant backups to cloud storage or a second external drive. That provides restore options if one drive fails.
While physical damage can sometimes be repaired to recover data, prevention is more effective. Following good computing practices for external drives avoids costly data recovery. Handling drives carefully, maintaining proper storage conditions, and backups provide the best protection.
