A Hitachi Touro Mobile that spun up normally and made a steady whirring noise while showing nothing at all. Of all the sounds a failing drive makes, this is the one that gets ignored longest — because it sounds like a drive doing its job.
The client plugged the drive in to show family their holiday photographs. It spun up, made a steady whirring sound, and displayed nothing. No error message, no prompt to format — a drive that appeared to be working and a computer that could not see anything on it.
They worked through the free checks: a different cable, a different port directly on the machine, then a different computer entirely. Identical behaviour each time, which correctly told them the fault was in the drive. The photographs existed nowhere else.
To read anything, a head has to know where it is — and it works that out continuously rather than by counting.
Interleaved with the data on every surface are servo wedges: short bursts of positioning information written at the factory, spaced evenly around each track. As the platter turns, the head passes over these hundreds of times per revolution, and the drive uses them to confirm its position and correct for drift, vibration and thermal expansion. It is a closed loop running constantly, and nothing can be read until it has locked.
A head that has degraded — a weakening read element, a failing preamplifier, a suspension slightly out of true — can still detect the surface but can no longer resolve those bursts reliably. So the drive seeks, fails to lock, recalibrates, seeks again. That cycle is the whirring.
From the drive’s own point of view nothing has failed yet: the read has not completed, so it keeps trying. It will keep trying for as long as it has power.
Clicking alarms people. It sounds wrong, most people unplug a clicking drive fairly quickly, and that instinct limits the damage considerably.
Whirring does the opposite. It sounds like a drive seeking, which is what drives do. So it gets left running. People try again the next day. They plug it into a third computer. They leave it connected while reading about it online. The drive accumulates hours it should never have had, because nothing in the sound says stop.
Each of those recalibration cycles passes the heads back and forth across the surface. Gentler than a head crash, and not free — a degraded head flying marginally low makes occasional contact, and every contact liberates particles that make the next contact more likely.
The drive was removed from its enclosure and examined before being run again. The heads were degraded rather than destroyed: reading intermittently, unable to hold position reliably. That is a considerably better position than heads that have made sustained contact, and the surfaces confirmed it — light marking only, no scoring.
A matched donor head assembly was fitted under filtered air and the internal recirculating filter replaced, since the debris already in circulation would otherwise have gone to work on the new heads within minutes.
Imaging began immediately, in short controlled passes with per-head timeouts, and it was ordered by what the client wanted rather than by address. The photograph directories were located in the file system first, translated to the physical regions holding them, and read before anything else. If a repaired drive gives only one good read, that read should be spent on the material somebody actually came for — not on the Windows folder, which happens to sit earlier on the disk.
From the completed image the file system was rebuilt, and every recovered photograph was verified by rendering rather than counting. A JPEG that lists at the right size and opens to a grey rectangle is not a recovered photograph.
About 98% of the photographs, returned on fresh media. The shortfall would almost certainly have been smaller had the drive not run for as long as it did.
Nothing the client did was unreasonable. The checks were sensible, they were carried out in the right order, and the drive did not sound broken. That is precisely the problem with this particular noise.
So the rule worth remembering: if a drive is audibly busy and showing you nothing, it is not working. It is failing, repeatedly, in a way that sounds like effort. Unplug it. External drives are from £300 +VAT, with a 50% deposit for clean-air work.
Send the device over with a short account of what happened to it. The diagnostic costs nothing and commits you to nothing, and the figure that follows is fixed in writing before anything is opened.
Nothing can begin until the device is on the bench, which makes this the only step that needs anything from you. Pack it properly, put your details in with it, and send it over. What follows is a free diagnostic and a written figure, in that order.
Posting it? Use something tracked and insured — whatever is on the drive is worth considerably more than the postage. Bringing it in? Weekdays, 9am to 5:30pm, and it still wants packing as above for the journey.
Tell us what the device is, what it is doing, and anything already tried — an engineer will come back with a realistic view of the odds and a price band, before you commit to posting anything.
We’ll be in touch shortly. For anything urgent, call 0161 871 0788.
Usually the heads seeking repeatedly and failing to lock onto the servo data that tells them where they are. The drive keeps trying because the read has not failed yet from its perspective — which is why it sounds busy rather than broken.
Slightly, in that the heads are generally not contacting the platter. In practice it often ends worse, because clicking makes people stop and whirring does not. The drive gets hours of repeated seeking it should never have had.
A different cable, a different port directly on the computer rather than through a hub, and a different machine entirely. Those cost nothing and resolve a real share of externals. Once they are exhausted, stop — repeated attempts are what reduce the recovery.
Usually a very high proportion, and they are prioritised during imaging so that the most important directories are secured first. Recovered images are checked by rendering rather than counting, because a file that lists correctly can still open to nothing.
It does. The 2.5-inch mechanisms in portable drives are more tightly built and get carried around, so head and bearing wear is commoner than in desktop units. They also tolerate less of the repeated seeking described above.
From £300 plus VAT for a single external drive, fixed in writing after a free 48-hour diagnostic, with a 50% deposit where clean-air work and donor parts are required.
Start with an instant online quote, or call and talk it through with us first. You'll have a clear, fixed price before any work begins.