| Hard Disk: An Introduction Hard disk is a | | | | the platters as they spin, allowing each head |
| non-volatile data storage device that stores | | | | to access almost the entire surface of the |
| electronic data on a magnetic surface layered | | | | platter. Contemporary hard drives use a voice |
| onto hard disk platters. Word Hard is use to | | | | coil actuator, which controls the movement of |
| differentiate it from a soft, or floppy disk. | | | | a coil toward or away from a permanent magnet |
| Hard disks hold more data and can store from | | | | based on the amount of current flowing |
| 10 to more than 100 gigabytes, whereas most | | | | through it.Fundamental structures of all hard |
| floppies have a maximum storage capacity of | | | | disk are same, and are composed of the same |
| 1.4 megabytes and in addition are faster too. | | | | physical features, but their performance |
| Normally term hard disk is much familiar with | | | | depends on the quality of their inner |
| computers only but it is widely used as | | | | components.Hard Disk Failure: Hard Disk |
| network attached storage for large volume | | | | Failure occurs when a hard disk drive |
| storage. Furthermore, appliance of hard disk | | | | malfunctions and the accumulate data cannot |
| drives spread out to video recorders, audio | | | | be accessed. It may happen in the course of |
| players, digital organizers, digital cameras, | | | | normal operation due to an internal or |
| and even in latest cellular | | | | external factor. Disk failure varies and the |
| telephones.Reynold Johnson invented the first | | | | most common is "Head Crash" where the |
| hard disk in 1955 for IBM 305 computer with | | | | internal read and write head of a device |
| fifty 24 inch platters and total capacity of | | | | touches a platter or magnetic storage surface |
| five million characters, and in 1956 - first | | | | often grinding away the magnetic surface. |
| commercial hard disk was launched with 5 | | | | Head hover just micrometers from the platters |
| megabyte capacity, the IBM 350 RAMAC disk | | | | plane which makes such collision a common |
| drive. Within time frame of 50 years and | | | | one. This sort of crash usually invites |
| rapid progress in technical enhancement, we | | | | severe data loss and unprofessional data |
| have now reached to latest 2006 - First 750 | | | | recovery attempts results further damage to |
| GB hard drive from (Seagate) and First 200 GB | | | | the remaining data. Hard drive also includes |
| 2.5" Hard Drive utilizing Perpendicular | | | | other controller electronics i.e., |
| recording (Toshiba).Heart of hard disk | | | | semiconductors, valves or electronic |
| consists of four basic components: The | | | | circuits, and major components such as |
| Platters: Platters are the actual disks | | | | Platters, Spindle Motor and Head Actuator. |
| inside the drive that store the magnetized | | | | Failure of any these devices may cause a hard |
| data. Conventional platters are made of a | | | | disk failure.Factors causes disk failure are |
| light aluminum alloy and coated with | | | | numerous, yet most common are power surges, |
| magnetize-able material but latest technology | | | | voltage fluctuations, electronic malfunction, |
| uses glass or ceramic platters as they are | | | | physical shock, wear and tear, corrosion, |
| thinner and also heat resisting. Most drives | | | | exposure to high magnetic waves, sharp |
| have at least two platters and the larger the | | | | impact, high temperature exposure etc.The |
| storage capacity of the drive, the more | | | | phenomena of hard disk failure is raising |
| platters there are.The Spindle Motor: Hard | | | | higher and higher; as to increase the read |
| disk drive consists of a spindle on which the | | | | and write speed, today we have latest hard |
| platters spin at a constant RPM. Moving along | | | | disk rotating amazingly faster and this |
| and between the platters on a common arm are | | | | immense revolving speed generates massive |
| read-write heads. The platters in a drive are | | | | centrifugal force, a single adverse cause in |
| divided by disk spacers and are clamped to a | | | | the course of normal operation can cause |
| revolving spindle that turns all the platters | | | | severe hard disk failure.Hard Disk Data |
| in a uniform motion. The spindle motor is | | | | Recovery: Hard disk data recovery is the |
| built right into the spindle and rotates the | | | | process of recovering the trapped data from |
| platters at a constant set rate ranging from | | | | the damage hard disk device, when it can not |
| 3,600 to 7,200 RPM.The Read/Write Heads: Read | | | | be accessed in normal circumstance. Several |
| write heads read and write data to the | | | | Techniques are used to retrieving data from |
| platters, and each head is fixed to a single | | | | damaged hard disk and techniques vary |
| actuator shaft so that all the heads move in | | | | accordingly. It can be done by moving disk |
| harmony. Typically, only one of the heads is | | | | drive to a working CPU, or may have to open |
| active at a time either reading or writing | | | | the disk drive and replace parts such as read |
| data. When not in use, the heads are | | | | write heads, arms and chips and sometime the |
| inactive, but when in motion the spinning of | | | | platters have to be removed and placed into |
| the platters generate air pressure that lifts | | | | another drive. Physical damage can not be |
| the heads off the platters. The space between | | | | repaired by the general users, as it requires |
| the platter and the head is so minute that | | | | clean and dust free lab environment, in |
| even one dust particle or a fingerprint could | | | | addition proper hardware and technical |
| disable the spin. When the platters cease | | | | expertise; where under microscopic |
| spinning the heads come to rest, at a preset | | | | examination with proper tool and techniques, |
| position on the heads, called the landing | | | | the damage drive is put on to observation for |
| zone.The Head Actuator: All the heads are | | | | data salvaging.In case of worse happening, do |
| attached to a single head actuator arm, which | | | | consult Digital Image Recovery Service for |
| moves the heads around the platters. The | | | | saving your important data trapped within the |
| Actuator arm moves the heads on an arc across | | | | damage device. |