A-LPC-to-Note: Hard Disk Drive Failure and Symptoms...

Hard Disk Failure and Symptoms
A hard disk drive (HDD) failure occurs when a hard disk drive malfunctions and the stored information cannot be accessed with a properly configured computer. A disk failure may occur in the course of normal operation, or due to an external factor such as exposure to fire or water or high magnetic waves, or suffering a sharp impact, which can lead to a head crash.

The severity of disk failures vary. Typically, a hard disk can fail in four ways that will lead to a potential loss of data:
1. Logical Corruption
2. Firmware Corruption/Damage to the firmware zone
3. Electronic Failure
4. Mechanical Failure

Combinations of these four types of failure are also possible. Over time, all hard disks will develop bad sectors which can lead to data loss and drive inaccessibility.
The data on the hard disk maybe recoverable, but depends on exactly what happened to the disk.

Logical Errors
Often the easiest and the most difficult problems to deal with, logical errors can range from simple things such as an invalid entry in a file allocation table to truly horrific problems such as the corruption and loss of the file system on a severely fragmented drive.
Logical errors are different to the electrical and mechanical problems (described below) as there is usually nothing physically wrong with the disk, just the information on it.

Firmware Failure
Hard disk firmware is the software code that controls, and is embedded in, the physical hard drive hardware. If the firmware of a hard disk becomes corrupted or unreadable the computer is often unable to correctly interact with the hard disk. Frequently the data on the disk is fully recoverable once the drive has been repaired and reprogrammed.

Common Firmware failures Symptoms:
• The hard disk will spin up when powered on, but be incorrectly recognized or not recognized at all by the computer.
• The hard disk will spin up & be recognised correctly by the computer but the system will then hang during the boot process.

Electronic Failure
Electronic failure usually relates to problems on the controller board of the actual hard disk. The computer may suffer a power spike or electrical surge that knocks out the controller board on the hard disk making it undetectable to the BIOS.

Common Electrical failures Symptoms
• The hard disk will not spin up when the drive is powered on - it will appear dead and not be recognized by the computer.

Mechanical Failure
Mechanical hard disk failures are those which develop on components internal to the hard disk itself. Often as soon as an internal component goes faulty the data on the hard disk will become inaccessible.

Common Mechanical failures Symptoms
• When powered on, the hard drive will immediately begin to make a regular ticking or clicking sound.

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