When individuals say their “hard disk drive (HDD) failed”, there can be up to four very distinct forms of HDD failure. These differences will be far greater than simply educational. Whether the form of failure is logical, mechanical, electronic or firmware will determine what may be safely attempted at home, what must be done in a laboratory environment and whether the contents of the HDD are recoverable. Below is a simple explanation for each type of failure, signs and symptoms to look out for when attempting to identify the form of failure present and what actions should be taken.
A logical failure occurs at the software level; these failures can frequently be resolved by utilising DIY solutions. On the other hand, mechanical, electronic, and firmware failures occur at the physical or lower levels and if the incorrect action(s) are performed on these types of faults, they will become even more problematic. Thus, the first step will be to accurately diagnose which form of failure exists.
A logical failure represents a software-based error in an HDD that is physically intact. Examples include a corrupted file system, an unintentionally deleted or damaged partition, an unplanned format of an HDD and/or a virus. The mechanical functions of the HDD are functioning properly; the issue lies in the “directory” of the drive that describes to the computer where files exist. It is this single category of failure where careful utilisation of DIY recovery software offers a viable means of success since the drive may be safely accessed/operated upon. The fundamental principle of recovering from a logical failure is to perform the recovery process to a different drive (and never write to the original drive). HDDs experiencing either a missing partition or an unintended format will typically contain extremely recoverable information.
One type of failure, mechanical failure, is when the head(s) are physically unable to read/write data on the disk. This may occur because the head(s) have lost their ability to move over the disk, or the disk’s spindle motor has lost its capability to rotate. Additionally, the bearings inside the drive could wear out. These causes produce audible noises (beeping, grinding, clicking) as the drive tries and fails to start. Because it is an issue with the drive itself, and not software, there is nothing software can do, and each time the drive is powered on again there is a greater chance that the heads will come into contact with the platter(s). Therefore, a mechanical failure requires opening the drive in a controlled lab environment, replacing the damaged part(s) with identical “donor” component(s), then imaging the contents read-only. This process is referred to as “bench work,” and should not be attempted at home, nor should the drive be powered up again until it is completed.
Another type of failure is electronic failure. Electronic failure occurs when there is some sort of damage to the printed circuit board (PCB) which houses the drive’s logic circuits. Damage to the PCB may result from an electrical surge, a lightning strike, a failing power supply, etc. Generally, an electronically failed drive will show no signs of life (it won’t spin, won’t beep, won’t be detected, etc.) and occasionally, a slight burning odour may emanate from the drive. Fortunately for those trying to recover data, the disks themselves and therefore your data will generally remain intact; it is simply the electronics that require attention. There are two basic methods of recovering data from an electronically failed drive. First, one could attempt to repair the damaged PCB. Second, one could replace the entire PCB. However, when replacing the PCB, it is critical that one replaces it with a PCB that was designed specifically for your drive. Most modern PCBs contain calibration data (ROM), specific to that particular drive, which must be transferred across. Failure to transfer this calibration data can make things worse. Again, this would best be performed on the bench by someone knowledgeable in the field of data recovery.
Each hard drive contains internal firmware. If this firmware becomes damaged, the drive may appear to operate as expected. It will spin up normally when powered on and the user should hear no unusual noises. However, the operating system will either report the drive as being unavailable, list the wrong total capacity for the drive, or show the drive listed under an unknown/odd device name. Because the physical aspects of the drive function properly, many users incorrectly treat the issue as simply a problem that can be resolved using software. But since software does not have access to the firmware layer, attempting to repair via software will fail. The solution involves accessing the service area associated with the drive via specialised tools. Once there, we will have the capability to rebuild/reload the firmware modules and then recover your data from the drive. In most cases, the data will remain intact and can be read once again. One of the lesser-known forms of failure, this is another example of why a correct diagnosis is so important.
There are four: logical (a failure at the software level, such as a corrupted file system, a deleted partition or a format), mechanical (worn heads, a seized motor, the classic clicking drive), electronic (damage to the circuit board, commonly caused by a power surge) and firmware (corruption of the drive’s internal software). Each type of failure needs a different approach, and only logical failures are safe to tackle with recovery software.
The clues are in the symptoms. Mechanical failures produce audible noises such as clicking, grinding or beeping. Electronic (board) failures result in a completely dead drive that is silent and undetected. With firmware failures, the drive spins and sounds normal but is not recognised or shows an incorrect size. A logical failure is a drive that works but has missing files, a lost partition or a format prompt.
Only logical failures, and even then only cautiously. A corrupted file system, deleted files, a lost partition or an accidental format can often be recovered using software, provided you recover to a different drive and never write data to the affected one. Mechanical, electronic and firmware failures are physical or low-level faults, so attempting to solve them through DIY methods will usually make them worse.
Most likely no. Normally in the case of a physical or electronic/firmware failure, the actual data stored on your hard drive is still intact. It was the heads, board or firmware that failed. Recovery requires that the drive is fixed sufficiently to read its contents one time while it is sitting on the bench, and then that data is imaged read-only. The primary danger to your data is powering on the drive after the failure occurred, not the failure itself.
Determine the nature of the failure based upon the symptoms. If the drive seems to have experienced a logical failure, immediately discontinue use of that drive, and retrieve as much of your data as possible onto another device. If the drive is making noise, has died completely, or seemingly works normally but acts erratically, turn off the power and avoid running any software on it. Those are indicators that there is some sort of physical or firmware issue requiring bench evaluation. When in doubt, a complimentary diagnostic will provide sufficient information regarding whether or not you have a logical failure versus a physical failure without jeopardising any of your data.
Regardless of the nature of the failure (or how it affects your ability to access data), send us your hard drive and we’ll determine both the nature of the failure and what portions of your data can be successfully recovered, along with a complimentary diagnostic and a fixed written quote prior to performing any recovery work regardless of the outcome of our testing.