Hard disk failure can be classified by nature or by reason of different types. In the following paragraphs, they are ranked according to the frequency of occurrence.
Damage to the electronics of a disc occurs most often by a power supply failure or a breakdown, for example, in the presence of atmospheric overvoltage. In most cases, the electronics inside the disc, integrated on the head bundle, is also defective. Such a damaged disk usually does not work at all or is heavily heating up, smells after burning, and sometimes even torn integrated circuits on its electronics.
The accompanying phenomenon may be that the disk is spinning and just buzzing with the heads of mechanical stops. In some cases it blocks (overloads) or destroys a good source. Hard disks typically have two electronics – a visible electronics with a power and data connector, depending on the type of disk and internal electronics, which is usually integrated directly on the head bundle, both because of the speed of data transfer and the resulting interference problems, because of the data wires, because this electronics always works with only one head addressed. Interestingly, unlike in earlier times, IDE and SCSI disks are the same, but they differ only in electronics. For IDE, electronics continue to be able to perform only one operation at the same time, SCSI electronics can perform multiple operations at the same time, and the command format is more efficient.
In this case, the hard drive repair and recovery usually requires replacement of both electronics. Simple replacement of the external electronics requires only tools and identical replacement of electronics, which means not just the same layout but also the same firmware version. Replacing the internal electronics is particularly difficult due to the risk of head or surface damage. There are no differences in the style of the external electronics firmware, and it is sometimes better to replace the entire header volume.
Protection against this type of fault is possible through a high-quality source with sufficient power and ideally PFC control.
Inoperative reading heads
This defect suddenly occurs and the disc starts to click on it regularly. Without the specialist diagnostics in the lab, it is almost impossible to distinguish from the case of surface damage. The defect can only occur on one of the whole head bundle.
Data rescue involves the use of a functional bundle of heads, but due to the possibility of surface damage, careful analysis is required. Recovery itself is 100% successful.
There is no special protection against this failure; it is a typical failure foreseeable with a certain probability. For hard disks, the most risky moment is the start or landing of the headers.
The flash driver repair is much easier than hard drive repair.