PC3000

What happens if you have a hard disk which spins erratically, or the heads are making clicking noises, or maybe everything seems fine but the disk is just not recognized by the PC or any other tool? Since you don't have access to the disk to recover data you may conclude that it is due to the controller board failure or some mechanical or physical damage, and whatever you try to do to recover data is then driven simply by your intuition because you have no information about the status of a drive that is simply not recognized by your utilities.