When a file is saved to a computer, the data is stored in the magnetic coating of the hard disk. This magnetic coating on the plates is the “glue” that holds your data. Any damage to this magnetic coating means that there is a loss of data, as each piece of missing coating contains data. Thus, a dish lacking some of that coating has a better chance of a successful data recovery, as opposed to a plate that had massive amounts of that magnetic coating removed or destroyed.
Hard disk trays, or spindles, are rotated by an electric motor. The speed of this rotation is measured in revolutions per minute (RPM) and the higher the hard disk performance … the higher the RPM that increases the reading and writing of data on the plates. Any surface contact with the discs can cause serious damage to the magnetic tape that contains the data. This includes dust, fingerprints, water and, most important of all, hard drive heads. Dish damage is the most serious type of damage to cause hard drive failure.
Heads (Head Crash) When the hard disk is not being used actively, the heads stop until the hard disk needs to read or write data again. It is when this head moves out of the super thin air cushion between the dishes that causes the head to collide and touch the plate of the hard disk.
Firmware Firmware is the program instruction located on the printed circuit board (PCB) chips. Each firmware revision is specific to your hard drive type and each hard drive can go through dozens of firmware revisions to increase the hard drive performance of that particular manufacturer. The older the hard disk, the harder it would be to find a functional firmware for that particular hard disk model.
Printed Circuit Board (PCB) The hard disk PCB is the hard disk electronics that manages and operates the hard disk. If a printed circuit board is damaged, it is often replaced by an identical printed circuit board with the same firmware on the original hard drive. Typically, PCB damage is caused by water or fire, but there are other reasons why the PCB would fail. And often a failed PCB affects other aspects, such as firmware or heads.
Types of Hard Drive Failure
In general, when a disk drive fails, it is due to one of the following causes:
Media failure also known as head fall (as described above), the hard disk heads touched and physically damaged the magnetic coating of the dishes.
Mechanical failure In general, any electronic fault on the hard disk falls into this category. Fire, water, electrical damage to the hard drive would require replacing parts.
PCB Failure as described above, PCB failure falls into the type of mechanical failure and can usually be “switched” by an identical PCB for that specific type of hard drive. Along with the correct firmware for this disk drive, a PCB replacement can be a difficult type of hard drive repair if the hard drive is an older model.
Logical Drive Failure this type of hard drive failure is usually the least damaging to the data. This type of error usually means that the computer’s operating system (or utilities) can see the drive, marked it as unallocated space, but because the computer’s MFT is corrupted or corrupted, the data can not be read. Hard drive failure of this type is not as destructive and the chances of a complete and successful data recovery are high.