Data Recovery Case File · Desktop Externals & Aging Drives · Working Is Not Undamaged
The Drop Caused the Fault and the Hours After It Caused the Loss
Her enquiry contains the detail that explains everything and is usually left out. A drive that stopped working "after a slight fall. It didn't stop working immediately — it did work for a few hours after the drop. Later on when I tried to use it at home, it didn't work" and now makes a repeating sound. An impact that does not stop a drive has not spared it, and every hour of use afterwards was a damaged head flying over the surface.
| Media | External hard drive following a minor fall — continued operation for several hours before failure; head positioning failure audible; academic content held with examinations pending |
| Reported situation | Drive dropped from a modest height · drive continuing to function immediately afterwards · normal use continuing for several hours · drive failing later the same day · repeating sound audible on connection · academic content required · examinations imminent |
| Fault class | Impact damage to the head assembly with progressive surface degradation from continued operation — debris generated during the period of use |
| Equipment used | Period of continued operation treated as the principal damage window · no further power-up permitted · laminar flow bench inspection with particulate and surface assessment before any spin attempt · matched donor heads as indicated · capture sequenced to required material first |
The decode: why continuing to work is not reassurance
What a modest impact does to a running drive: the heads are flying at a height smaller than a smoke particle, held there by airflow. A knock can displace one, bend its suspension slightly, or bring it into brief contact with the surface — none of which necessarily stops the drive.
Why it keeps working: because a head that is damaged is still a head. It continues positioning, continues reading, and continues flying — imperfectly, at a wrong height or a wrong angle, but well enough that nothing announces itself.
What happens during those hours, and this is the part that costs: a damaged head passing over a platter thousands of times per minute either touches the surface or flies close enough to disturb it. Each pass removes a little material, and that material becomes debris circulating inside the sealed enclosure — which then damages the head further and scores the surfaces it lands on.
So the arithmetic is the wrong way round from how it feels: the drop created a fault that might have been recoverable cleanly. The hours of use afterwards are where the surfaces were damaged, progressively, while everything appeared normal.
Why the repeating sound now: that progression ends with a head assembly that can no longer position reliably. The sound is it trying, failing to find its reference, parking and retrying — the terminal state of what started with the fall.
So the rule worth taking from this, and it applies to every drive: a drive that survives a drop should be copied immediately and then retired. Not tested to see whether it is fine — copied, because working is not the same as undamaged, and the window in which it still reads is the only thing worth spending.
Why nobody does this: because a drive that still works is enormously reassuring, and the natural conclusion is that the fall did no harm. The evidence for damage is invisible and the evidence for it being fine is right there on the screen.
What must stop now: all power. Each attempt spins a mechanism whose surfaces may already carry debris, and grinds it further in.
On the deadline: naming exactly what is needed lets capture reach it first and confirm early.
On the bench
The period of continued operation was treated as the principal damage window — an impact displacing or damaging a head without necessarily stopping the drive, after which it continues flying at a wrong height or angle, removing surface material with every pass and generating debris that circulates within the sealed enclosure. No further power-up was permitted. Inspection ran under the laminar flow bench with particulate and surface assessment before any spin attempt.
The outcome
The hours of continued use treated as the damage window, no further power-up permitted, and surfaces assessed before any rotation. Free assessment, one fixed written figure including VAT, 50% of parts and labour upfront with the balance only on successful recovery. The decode: the drop made the fault and the hours afterwards made the loss. A damaged head keeps flying, imperfectly, removing a little surface with every pass — and that debris then damages everything it touches.
Drive that survived a drop and kept working
Copy everything off immediately and then retire it — don't test it to see whether it's fine, because working is not the same as undamaged. An impact can displace a head or bend its suspension without stopping the drive, and a damaged head keeps flying, at a wrong height or angle, removing a little surface material on every pass. That debris then circulates inside the sealed enclosure and damages whatever it touches. So the hours of normal use after a fall are usually where the real loss happens, invisibly, while everything on screen looks perfectly fine. If it has already failed, stop powering it.
Stop powering it — call Oxford Data Recovery on 01865 593000; the period of use treated as the damage window, surfaces assessed before any spin attempt, capture sequenced to what you need first.
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Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.