When a hard disk drive is dropped the effect of the impact is likely to be disastrous, particularly in the event of powering it back on again. The alignment of components within the drive can be severely disturbed by any impact, which could result in the read/write heads impacting with the surface of the platters if the drive is powered on.
Dropping a laptop, external drive or disk prior to installing into a server, from even a modest height can cause damage to occur, leading to the failure of the hard disk. You should not panic and avoid powering the drive up, as this could severely complicate the data recovery process. When such a drive arrives for data recovery, the disk will need to be dismantled and rebuilt using donor components in order for the raw data sectors to be successfully recovered. Always indicate that the drive had been dropped, as it will ensure the DiskEng hardware data recovery specialists know how to proceed without risking any further unnecessary damage.
How an Impact Damages the Drive
When a drive suffers an impact, it is most likely that two problems will occur, either of which will render the drive inoperable. The read/write heads can easily be damaged during the impact or the spindle motor assembly can seize. Often only one of these two failures are present, but when both occur, the chances of serious damage are increased. This is most likely to occur when the drive is running at the time of the impact, in which case the disk must be powered off immediately to avoid a total catastrophic failure.
Even if the read/write heads are not damaged, it is likely that the alignment will have been lost. This alignment is essential for reading the data, without which data will either be read slowly or not at all, especially if the read/write heads come into contact with the surface of the platters.
A failure of the spindle motor, with either cause the drive to seize up, or damage the alignment, causing a vibration in the platters, which could lead to the read/write heads impacting with the plater surfaces. This will result in the loss of raw data, which could if left unchecked result in a complete loss of data.
Dropped Hard Disk Recovery
Do not power your drive, laptop or server on after an impact has occurred. Although laptops and external drives are the most vulnerable storage devices to being dropped, as they are often moved about, dropping a hard drive during shipping or installation sometimes occurs. Accidents, such as kicking a server may also result in the same damage, so placing it under a desk may leave it vulnerable.
All hard drives which have suffered impact damage will need to be dismantled and rebuilt in a clean environment by a qualified data recovery engineer. Whether the drive was operational at the time or turned off, damage to the platter surfaces is often encountered, which can complicate the recovery process. Never attempt to recover the data yourself, as turning the drive on may result in data recovery being impossible.