Recovery Company
in Greece, since 2001
PCWorld 08/2011

Unfortunately, these symptoms usually indicate a mechanical problem within the disk. Of course it is not certain that your disk definitely has a mechanical problem if you have any of the above behaviors. For this reason the disk is examined thoroughly with special diagnostic tools before the company decides for the existing damage.
Change heads in hard disk
One of the most common but certainly not so simple problems are damaged heads or weak heads in a hard disk. This problem usually occurs when:
When there is a problem in the heads of the hard disk, usually a strange noise is heard from inside the drive that assures us that something is not working properly inside. In this case, the operation requires specialized knowledge, tools and the availability of clean room for the process of changing heads, as it is a very delicate process that can cause permanent data loss if not done correctly.
Also most of the time for the completion of the procedure is necessary to supply compatible donor hard disk to extract the head and place in the problematic drive. Also the existence of specialized equipment to examine the firmware of the disk after the change of heads is necessary. This raises the final cost of data recovery.
Problem with the motor of the hard drive
Another problem often found in Seagate drives is the jam of the motor of the disk, ie the axis that rotates the platters of the disk. Sometimes the motor, due to overheating, the volume it occupies change and because the margins on which moves are very narrow, it jams thus preventing the disk to rotate the platters.
Such a situation requires the extraction of the motor using specialized tools, always in a clean room