Repair the hard disk drive, Image the drive to a new drive or a disk image file, Logical recovery of files, partition, MBR and filesystem structures, Repair damaged files that were retrieved, usually, there are four phases when it comes to successful data recovery, though that can vary depending on the type of data corruption and recovery required.
Repair the hard disk drive (Phase 1)
Repair the hard disk drive so it is running in some form, or at least in a state suitable for reading the data from it. For example, if heads are bad they need to be changed; if the PCB is faulty then it needs to be fixed or replaced (hard drive pcb swap); if the spindle motor is bad the platters and heads should be moved to a new drive.
Image the drive to a new drive or a disk image file (Phase 2)
When a hard disk drive fails, the importance of getting the data off the drive is the top priority. The longer a faulty drive is used, the more likely further data loss is to occur. Creating an image of the drive will ensure that there is a secondary copy of the data on another device, on which it is safe to perform testing and recovery procedures without harming the source.
Logical recovery of files, partition, MBR and filesystem structures (Phase 3)
After the drive has been cloned to a new drive, it is suitable to attempt the retrieval of lost data. If the drive has failed logically, there are a number of reasons for that. Using the clone it may be possible to repair the partition table or master boot record (MBR) in order to read the file system’s data structure and retrieve stored data.
Repair damaged files that were retrieved (Phase 4)
Data damage can be caused when, for example, a file is written to a sector on the drive that has been damaged. This is the most common cause in a failing drive, meaning that data needs to be reconstructed to become readable. Corrupted documents can be recovered by several software methods or by manually reconstructing the document using a hex editor.