There are basically 4 ways to be "dead" (silent and undetected, spinning but invisible, clicking, or detected with nothing on it). There isn't much that connects them other than the term people use to refer to them. Two of them are among the more recoverable faults we handle.
Most drives described as dead are electrically dead and mechanically untouched. Therefore the data is completely intact. It is simply unreachable. It's a lot better off than it sounds.
30 seconds of observation will change everything that follows.
Hold your hand on it. If you feel nothing at all, this usually points to a failure of the circuit board and not the mechanism. This keeps the platters and your data intact. One of the better diagnoses available.
It appears to operate perfectly; it reports that there is no capacity or displays a blank model. The service area with the drive's own firmware has become unreadable, and all user data is typically intact behind it.
Mechanical. It is deteriorating every minute it runs, and speed is actually an important factor for this one category. Power it off now.
There is nothing mechanically wrong. A lost partition; a file system problem; a formatted volume — the "map" is bad and not the data.
Most commonly misunderstood symptom of data loss.
A drive that can do absolutely nothing can seem to be the worst possible outcome. In reality, it's often the best; as the board is typically engineered to fail first — most drives contain a TVS protection diode that will short-circuit and destroy itself if the supply voltage becomes too high — and the objective is for the surge to never reach the mechanism.
If that happens, the drive consumes zero power and performs no function whatsoever; meanwhile, the platter(s), the head(s) and every single bit of your stored data remains perfectly unchanged. A board level repair is required; which involves a matching donor board with the original ROM chip transplanted across. Modern drives store unique calibration parameters specific to each individual unit on that chip.
The one exception to turn what was previously acceptable into unacceptable is repeated attempts. Repeatedly powering a drive with a shorted board can allow a localised electrical fault to make its way to the motor.
You're not hiring someone to determine these.
Severely scored platters. Heads have removed the magnetic coating from that part of the band. Undamaged areas of the same platter will still show an image; however, since some of the information was erased, the result is a partial recovery with the missing files named individually.
Overwritten data. If you write new data to the original file area, it will destroy that piece of data completely. In addition, there is no residual magnetic signature left behind for any hard disk manufactured in the past two decades to recover from.
Encryption without the key. Any data recovered from a perfect copy of a drive is non-readable. When attempting to retrieve a lost password, our company does offer password recovery services. Password recovery services work best when a user knows some or most of their password. It does not work against a long random one.
Everything else on this page is a question of time and money rather than feasibility. For example single hard drives located within Manchester are from £300 +VAT after a free 48-hour diagnostic, with a 50% deposit where donor work is required.
Frequently, and silence is often encouraging. Most of the time when you see a silent hard drive, the problem is usually a dead circuit board rather than a broken mechanical part – and boards are designed to be sacrificed by failing a protective diode to keep surges from reaching the platters.
Usually firmware. Hard drives have an operating system stored as firmware on a reserved service area on the surface of the disks. If a module becomes unreadable then there is no way for the drive to explain what it is doing — therefore, it says nothing while acting completely normal. Data typically remains intact.
Not on anything made in the last two decades. Every hard drive is built with an individual calibration and those calibrations are stored in read-only memory (ROM) chips located on their own printed circuit boards (PCBs). So, when transplanting a PCB from one unit to another, if you do not include that ROM chip's calibration data then your unit will not initialise properly and/or may not accurately control the position of the heads.
No. When a hard disk fails to start or gives off a burnt smell, attempting to use it again risks turning a "contained" failure on the circuit board into an "uncontained" failure affecting other parts of the drive including motors and heads. Do not attempt to reuse after the initial failure.
Yes, generally speaking. The clicking that occurs when you run a hard drive is due to mechanical deterioration. Every minute you run a failing drive, its condition deteriorates. If a drive fails and then sits silent in your drawer it will continue to sit silently – in other words – it has not continued to fail.
Severely scored platters where the coating has been scratched off, an area which has been truly overwritten, or an encrypted volume where the encryption key is either lost or impossible to guess. The other cases involve a matter of time and money as opposed to possibility.