Overview
Modern computer system hard disk drives can contain a vast amount of data. So when the hard drive fails, and there are no recent backups available, data recovery is the only option available.
Introduction
A hard drive consists of a number of component parts. Each of which has its own failure modes.
1. Electronics
2. Mechanics
3. Firmware
4. Logical
Electronics
The circuit board on a hard disk is the ‘brain’ of the hard drive and a single component failure will render the drive useless. Data recovery from drives with electronics failures requires highly skilled electronics engineers who can to make temporary repairs in order to recover the data.
There are also electronic parts inside the hard drive that are vital for the correct functionality of the hard drive and consists of the head pre-amplifier circuit.
Mechanical
The critical mechanical parts of a hard drive comprise of, the actuator arm, the motor and the platters. (There are other Mechanical parts, vibro-acoustic components, filters, VCM Magnets, etc, but these are less critical).
The majority of mechanical breakdowns involve the Head pre-amplifier. Whilst this is not exactly a mechanical failure, the way that the head pre-amplifier is attached to the head stack means that when it fails it involves the replacement of the entire head stack assembly.
The next biggest cause of failure is motor failure. This is probably the most serious problem and requires specialist equipment so that platter alignment is not lost when removing and replacing the motor. Main problems with motors are burnt out coils and seized bearings.
Firmware
The firmware area or System Area (SA) is a region on the hard drive that contains the manufacturer’s proprietary information such as
- Self test logs
- Zone Tables
- SMART Logs
- ATA Password Information
- Security Data
- ROM Overlays
- Primary Defect Maps
- Operational code
and many others
For a hard drive to function properly it is vital that the Firmware Zone is error free. Working on the Firmware on a hard drive is a highly skilled job and requires specialist equipment. Making a mistake when changing the information in the Firmware of a hard disk can render a drive useless.
Logical
Logical problems are where there is nothing physically wrong with the hard drive and it is fully functional. Logical problems are where data has become inaccessible for some reason, for example, the user has deleted the files, the computer has come under virus attack. The skill set of the engineer requires experience of how the operating system that the data was stored on works. Also, an understanding of the structure of individual file types so that quality of files can be determined on a bulk and individual basis.
Data Recovery from Hard Drives
MjM Data Recovery Ltd
