Disk failure/data loss falls under a number of categories, including:

• Operating system corruption
  
  
• File system corruption
  
  
• Operating System Re-Installation/Re-formatting
  
  
• Disk Partitioning
  
  
• Accidental or malicious deletion
  
  
• Firmware corruption
  
  
• Disk Motor Failure
  
  
• Disk Head Failure/Crash
  
  
• Disk Platter Surface Defects
  
  
• Seized drive mechanism
  
  
• Electronic failure

We use a controlled environment to minimise particulate contamination when hard disks need to be opened to determine the failure mode, and to make necessary repairs prior to recovering the data.  Conducting ‘open-drive’ work in a normal workshop environment can be catastrophic to the platters and heads when the drive is spinning.