We all know about the ‘safely eject’ option for our external hard drives and flash drives. Some of us joke that ‘life is too short to safely eject’ which, although funny, could hold some dire consequences.

As a hard drive operates the platters spin at a few thousand revolutions per minute whilst the heads fly nanometers above the surface, reading and writing information. These days, the heads park on a ‘parking ramp’ when the drive is powered off or the drive is not in use. You can see the parking ramp and parked heads in the article about the insides of a hard drive. With certain models of hard drives, if power is lost whilst the drive is still busy with a read or write operation, the heads can remain over the surface of the platters whilst the drive powers down and the platters stop spinning. In this case what happens is, instead of the heads parking safely on the ramp, they stop on the platter surface and stick. The heads are never supposed to make any physical contact with anything, they fly just above the surface due to the air bearing effect when the platters spin.

Below you can see a case of so-called ‘stiction’, where the heads did not park correctly on the parking ramp, but fell just short and instead stuck to the edge of the platters. Another mm and they would have parked properly, so this customer was very unlucky. Data recovery from this sort of fault involves removing the heads from the platter surface, inspecting them for damage microscopically, and reinstalling if found to be safe. If the heads are damaged then a new donor set of heads from an identical hard drive are installed in the lab. Once this has been done, we use specialist data recovery hardware to image (clone) the hard drive as this hardware can work around the bad and unreadable areas of the drive which will have developed over the areas where the heads became stuck.

Portable 2.5″ Seagate 1TB hard drives are very prone to this. Inside the enclosure you will often find a Samsung hard drive model number ST1000LM024. We have successfully performed data recovery in our Cape Town office on countless drives with stiction. If you have a Seagate or any other hard drive, always be sure to safely eject it when removing it, and shutdown your computer properly as this can affect internal hard drives as well. Rather be cautious otherwise you might need to use our data recovery service.

faulty hard drive for data recovery




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