When you have lost access to your data one of the first and most useful steps you can take towards determining the cause of the hard drive failure is to listen to your hard drive. The sounds that it makes when power is first applied may provide a great deal of information regarding what has gone wrong.
The purpose of this short article is to provide sound samples of hard drives which have suffered some of the more common forms of physical hard drive failure. The sounds here are from hard drive recovery tasks where all access to the user data had been lost. If your hard drive is making strange sounds but you still have access to your data then first of all copy all of your vital data to a second location (you can then investigate the strange sounds at your leisure).
The first task is to remove the failed hard drive from the computer chassis in order that you can listen to it without the distractions of cooling fans / other hard drives within the computer. The easiest way way to do this is simply to run the power cable to the hard drive as shown below (if the power supply cables are long enough to permit it).
Where this isn’t possible either get your ear as close as possible to the hard drive or you could invest in a cheap stethoscope (a few pounds will get you one on ebay).
What Does a Healthy Hard Drive Start-up Sound Like?
When power is applied the drive should spin the platters inside the chassis first, this will typically sound like a low hum which rises in pitch as the speed of rotation of the platters increases. This will be followed by a short burst of ticking/scratching sounds as the heads leave their parked position and start to search the platters, you will usually have to get your ears very close to the drive to detect this. The heads will not make a move until the platters have reached their full rotation speed, the delay between the hum as the drive platters begin to spin-up and the heads making their first move can vary from seemingly almost instantaneous, up to 10 seconds or more depending upon the type of drive. The initial burst of noise from the heads should last no more than a few seconds and then the drive should quieten down. At this point the sounds from a healthy drive will be a steady hum from the platter rotation and the occasional ticking/scratching sound from the heads at irregular intervals.
There are two sizes of hard drive (that is to say physical chassis dimensions rather than storage capacity). They are usually referred to as laptop (or 2.5”) and desktop (or 3.5”). each has a different power-up sound and each is more vulnerable to different forms of physical hard drive failure. The following are examples of the start-up sounds from healthy 2.5” and 3.5” drives. Click on the links below to hear them (you will need the volume set high)
Different models (even different individual hard drives of the same model) will have variations on these sounds, but the same sequence of sounds will broadly apply for all healthy hard drives. There is a selection of other healthy hard drive start-up sounds at the end of this article.
What Does a Hard Drive that has suffered a Physical Failure Sound Like?
As you might imagine that will depend upon the nature of the hard drive failure. For the purposes of this article we will consider 3 scenarios:
1. The hard drive is suffering from damaged read/write heads.
2. The platter motor which should spin the platters inside the hard drive chassis has become seized.
3. The read/write heads have crashed into the platters and are now preventing the hard drive from spinning-up.
For a quick introduction to hard drive anatomy have a look at our article here.
The Hard Drive Failure was Caused by Read/Write Heads Having Failed:
Where this has happened the hard drive will typically first spin-up the platters. Once these are up to speed the heads will attempt to read from the platters. They will of course fail to read and the drive will typically reset the heads. This results in a hard click as the heads hit a physical backstop in their parking area and then move out to try to read from the platters again. This sequence will often (but not always) be repeated until power is removed, leading to a repetitive clicking sound:
Sometimes the platter motor may also restart between boot-up attempts and the motor will rev:
It can also be the case that the hard drive failure takes the following form, it spins-up, the heads attempt to read, fail to do so and the drive then simply shuts-down:
It is important to understand that there are other possible causes of these sounds besides damaged read /write heads.
The corruption of a hard drive’s firmware can result in the same repeated-attempt-to-boot behaviour and therefore of course identical start-up sounds. Firmware is a highly specialised area of data recovery, for more information have a look at this article. Suffice to say that it is essential that corrupted firmware is eliminated as a possible source of these sounds before any more drastic action is taken.
The worst case scenario is that these sounds are caused by physical damage to the platter surfaces. This could be as a result of either the heads having impacted the platters (typically when the hard drive was knocked or dropped) or through degradation of the platters surface resulting in flakes of the platter itself breaking off. Platter damage is particularly bad news because usually the damaged area of the platter will in turn wreck the read/write heads. The platters are typically spinning at anywhere from 4,200 to 10,000 RPM just a tiny fraction of a millimetre below the heads, the slightest damage to the platter surface is therefore like smashing the delicate heads into a brick wall at high speed. Platter damage means that there is little point in replacing the failed heads because the new set of heads will suffer the same fate when they hit the damaged area of the platter.
When your hard drive is making these sorts of sounds there is not much that can be done for hard drive recovery either at home or via a non-specialist data recovery company. The requirements for such a drive are:
-Confirm that the hard drive firmware is intact (this requires specialist equipment and experience).
-Inspect as much of the platter surface area as is practicable for physical damage (of course this must never be done out-with a clean-room environment).
-Where applicable obtain a closely matching donor hard drive and carry-out a read /write head swap.
Hard Drive Failure Due to a Seized Platter Motor:
This is almost always the result of a physical knock to the drive although many people are shocked when they discover how slight a knock is required. We have seen drives suffer a seized platter motor when the hard drive has simply fallen over onto its side (as opposed to having been dropped from a height). It is much more common for an external hard drive rather than one fitted within a computer chassis to suffer from this form of hard drive failure for the simple reason that such drives are more likely to take a physical hit. It is also much more common for 3.5” desktop hard drives to be affected. The laptop sized 2.5” drives rarely suffer from seized platter motors.
Where this has happened the motor bearing has literally seized and on application of power the drive platters cannot spin-up. Typically a pulse can be felt through the chassis every second or two as the drive tries (but fails) to get the platter motor to start. This pulse is usually accompanied by a short humming sound:
If a drive has suffered a seized platter motor then to achieve a hard drive recovery it will be necessary for an expert with access to a clean room environment to perform a procedure called a platter swap. The platter motor is built into the chassis of almost all hard drives and so the requirements are to acquire a closely matching donor hard drive and relocate the data platters, read/write heads and the printed circuit board from the original defective drive to the donor chassis in order to use its platter motor. This is a challenging procedure even for the experts and only has a realistic chance of success if there was no platter damage caused by the original impact on the hard drive.
The sounds and feel of a hard drive with a seized platter motor are almost indistinguishable from the last of the physical failures covered in this article:
Hard Drive Failure through the Read/Write Heads Becoming Stuck to the Platters:
Sometimes the read/write heads can impact with and subsequently stick to the data platters (for a more detailed account of this problem please refer to our article here ). As the heads are literally stuck to the platters they prevent them from spinning-up when power is applied.
This failure mode is much more common with the laptop (2.5”) as opposed to the full size hard drives. While these sounds are commonly encountered with failed 3.5” drives, nine times out of ten the cause will be a seized platter motor.
The first task to be carried out is to remove the read/write heads from the drive. Needless to say this should only be done by an expert in a clean-room environment, trying this at home will almost certainly mean the end of all possible hope for data recovery. The heads must be removed without causing additional damage to the platter surfaces.
More often than not the heads will have been damaged in the impact with the platters and will need to be replaced with heads from a closely matching donor drive.
The sound samples featured in this article are representative only, each drive has its own unique sound on power-up. Here are some more examples:
Some more examples of healthy hard drive sounds:
Some more examples of hard drive failure sounds:
While it can be seen that there isn’t much scope for DIY recovery work when your hard drive is making the noises described in this article it will hopefully be of use in determining what has happened to cause the physical hard drive failure and subsequent lack of access to your critical data.