In the thirty years since IBM launched their personal computer, data and data storage devices have become such an integral part of people's lives that it seems almost unbelievable that in the 1980s very few people had their own computer at home. In 2009, the Office for National Statistics reported home computer ownership in the UK to be 75%, rising to 98% in the highest income group. Data and its safe storage has therefore become an increasingly high priority in people's lives, and the technology industry has responded to this need by creating ever higher storage capacities both in personal computers and external hard drives (EHDs).

EHDs offer many advantages to the user; they can protect a user's data by providing a back up capability for the main computer, they are useful for storing and archiving large multimedia files and the increasingly popular compact portable versions are particularly useful for data transportation. However, despite all their advantages, we need to be careful with these disks. EHDs are among the most common of all devices sent to data recovery companies. There are two main reasons for this:

1. EHDs are vulnerable to human clumsiness. Desktop EHDs may have liquids spilt on them or they may accidentally be pulled over or dragged onto the floor by trailing data or power cables. Portable EHDs are often placed into trouser pockets or bags which may be sat on or otherwise damaged during transit.

2. In their attempts to keep EHDs as compact as possible, manufacturers often omit the cooling fan which would always be found in a PC or laptop hard drive. EHDs are therefore at risk of overheating which can have repercussions for the stability of the data stored on the disk.

So, how do we know when and why our EHD has failed? And more importantly, what can we do about it? Well, in addition to the drive spinning then dying or not being recognised in the BIOS, there are a variety of noises that damaged EHDs can make, including screeches, beeps, bleeps, ticks, knocks and buzzes. We will take a look at some of these symptoms in more detail and describe the underlying causes:

* Beeps, bleeps and screeches: Many manufacturers use Fluid Dynamic Bearing (FDB) technology in preference to ball bearings as the disks run more quietly and have better shock resistance. However, our research has shown that when the disk is powered on from cold the fluid takes time to reach its optimum viscosity, and during this time is vulnerable to vertical vibration. This can lead to read/write errors and a resultant beep or bleep noise.

* Buzzing: EHDs contain a spindle which is responsible for rotating the platters. Only a small part of the spindle comes into contact with a comparatively heavy part of the drive, and a sudden knock or jolt to an EHD can cause the spindle to seize, and the drive will not be recognised by the computer.

* Ticking or Knocking: Inside EHDs there is an arm with read/write heads which, as their name suggests, read or write data to and from the platters. If there is damage to the heads or the motor, the arm can knock against other components in the disk as it continually tries to read the data, which creates a regular ticking sound. In our experience this is usually caused by the EHD being dropped or knocked over.

* Running slowly and suddenly dying: This may have accompanying noises (such as a repetitive scratching sound) and is caused by overheating due to lack of ventilation around the disk.

There are therefore many problems that can befall EHDs and preventing these by taking care of the disks is important; however should disaster strike the crucial piece of advice from the data recovery industry is to immediately power off the disk, and not to risk running a repair utility which may further damage access to the stored data. Reputable data recovery companies use specialised equipment and clean room laboratory conditions to retrieve valuable data. Their expertise and experience is reflected in the prices they charge; unfortunately there are many companies, typically those at the low end of the market, who greatly exaggerate their abilities. Potential customers would be well-advised to carefully research the reputation and skill-sets of data recovery companies before entrusting them with their crucial files.

Source by Sue Bellass