In our practice we often work with hard drives which have sustained a fall. Regardless of whether they are external hard drives or embedded inside of a laptop, any type of fall can result in irrepairable damage to the physical drive, specifically to the read/write heads and/or the reading mechanism. The read/write heads can twist or skew, separating from the actuator arm. When the actuator arm is not in use it is typically positioned in what is called a ‘park ramp’, where the read write heads stay when not in use. If in this position when the hard drive is dropped there should not be any damage to the disks or platters where the data is stored. However if the drop occurs when the read/write heads are in use this can cause the heads to scrape the surface of the platters, and thus may destroy valuable data.
Dropping a hard drive may also result in damage to the component that spins the disks at high speeds, called the spindle motor assembly. In this instance the hard drive would need to be brought into a dust-free environment, dismantled and the disks removed and replaced onto the drive shaft of another hard drive. This is a very delicate and time consuming process and should be be attempted by amateurs. These disks need to be aligned precisely or can result in permanent data loss. These type of repairs can cost anywhere from $1500 to $3200.
That being said, users should not automatically assume their hard drive repair will cost this much. If the fall resulted in the read/write heads magnetically adhering to the disk surfaces, this would prevent the disks from spinning and less damage might have occurred. Provided that the read/write heads have not been damaged, they can be moved back into their parked position and the disk surfaces cleaned. This process would cost approximately $700 to $900.