The noise is the head assembly repeatedly returning to its reference point to try again. It is the one symptom where the cost of ignoring it is simply measured in minutes. An example: an IBM Deskstar with a degree on it.
The drive cannot access the servo, so it will reset the heads to start over again, over and over, and if the heads are damaged they continue to drag their way back and forth on top of the platters that hold your files.
Platters provide the head position data (servo info) that the hard drive uses to determine the current location of the heads. All reads start with a search for this location. When the heads can’t find their locations, they move back to their “home” positions in order to reposition themselves and try again. It’s during these moves that your heads have hit the end stops and created those annoying clicks. This clicking is not itself damage; rather it represents the hard drive’s attempts to recover from an error caused by damaged heads or other mechanical failure issues. Any damage happens alongside the clicking if the heads are physically compromised.
This is why this issue has an urgency to it that “slow” does not. A disk that is failing due to bad sectors will continue to fail over time (weeks). A disk that is experiencing mechanical failure (due to a bad head) can experience complete failure within minutes of being powered on.
A steady click every second or two, indefinitely, indicates a head or servo failure. Three or four clicks then silence and spin-down in most cases means the drive failed and automatically went into park, usually indicative of some type of firmware or service area issue as opposed to actual head failure, which, while still serious, is a much less severe condition. Clicking that began after a drop is likely a head crash. A scraping or grinding note mixed in with the clicking indicates contact with the platters and it continues to cause damage with each revolution.
None of these patterns change the action. All of them mean a power down.
Freezing. There’s some theory behind it that the contraction of components frees up a stuck one. In reality when your drive comes back to room temp, you’ll develop condensation in all areas where there is air movement and/or heat transfer; and since those heads are only a fraction of a hair’s width away when they’re flying across the platter, condensation can be very damaging. It’s also unreliable and it creates a lot of problems if we need to recover data from your unit professionally.
Tapping or shaking it. Every now and then you might be able to get a dead drive spinning again just by banging on it. And that’s actually the danger because every time you hit the thing you’re encouraged to try again, even though now your heads may be hanging onto your platters instead of floating above them.
We open up the drive and replace the bad head assembly with good ones from a donor of the same type, version number, firmware revision, and head configuration. However, if your platters got damaged (even slightly) in the crash, that damage is going to remain forever, and that’s precisely why how long your unit runs after it starts clicking is such an important part of how successful a recovery will be.
Then the drive is “imaged,” or copied, in very small sections (controlled passes), using the most important parts of the drive first. One drive costs from £300 +VAT after a complimentary 48-hour diagnostic; there’s a 50% deposit required when we start doing donor work and you won’t be asked to pay anything else unless we’ve successfully completed the recovery.
The drive’s mechanical heads can’t find the servo information they need, so they don’t know where to look. Therefore, the heads retract, re-calibrate themselves and try to locate the servo information again. This click is the heads hitting their stop as they retract. At this point, the heads have stopped being able to read anything off of the drive, and if they are damaged, each attempt will cause further damage.
There is no way to make it functional again, and certainly not at a desk. Recovery means taking the drive apart, replacing the heads with a compatible donor head assembly, and copying the contents onto another media source in very small pieces (short passes). We don’t expect the drive to work afterwards; the goal is to recover your files/data, not restore your hard drive.
No. This process creates condensation on the disks as they return to room temperature, and this is extremely damaging to where the heads fly. This method has never been reliable, and it makes professional recovery more difficult.
In no case should you ever try to do so. Head damage will always degrade over time while running, but unlike most other errors (like bad sectors, which worsen over weeks), head damage will get worse over each minute of run-time: each time the damaged heads rotate across the surface containing your data, there is potential to ‘scratch’ that area. Turn it off now and keep it off.
Recovery costs from £300 +VAT for one disk. We provide a fixed written quote after the initial free 48-hour diagnostic. For donor-part work we take a 50% deposit, and charge the remaining amount only once we have successfully recovered the data.