Data Recovery Case File · Desktop Externals & Aging Drives · Identify Before You Commit
Establishing Which Drive Holds the Content Is Cheaper Than Recovering the Wrong One
His enquiry poses a practical problem alongside the technical one. Two external drives that "became inaccessible at the same time" after a suspected power event, both of which "start spinning but after a few seconds they click and stop" — and then: "one drive actually has no data on it, but my problem is I do not know which one." That question is answered before any recovery is scoped, and answering it is a fraction of the cost of guessing wrong.
| Media | Two external hard drives failing simultaneously — both spinning briefly then ceasing with audible activity; one believed to hold no content, with identification unknown |
| Reported situation | Two external drives becoming inaccessible at the same time · a power event suspected as the cause · both drives spinning briefly on connection · both ceasing after a few seconds with audible activity · one drive understood to hold no content · the owner unable to identify which · both drives offered for examination |
| Fault class | Simultaneous failure indicating a common cause — content identification required before recovery is scoped; both members needing assessment regardless |
| Equipment used | Content identification established at assessment before recovery was scoped · simultaneous failure treated as evidence of a shared cause · both drives addressed directly with imposed timeouts on controlled equipment · current draw measured across the start-up cycle per drive · recovery performed on the identified drive with the second held pending |
The decode: how the empty one is identified, and what simultaneity indicates
Why the question can be answered without a full recovery: occupancy is established early. Determining whether a volume holds content requires reading its structures, not extracting anything.
Why that is a small fraction of the work: it stops at the description. An assessment that identifies which drive is occupied has done a few minutes of reading rather than hours of capture.
Why both must nonetheless be assessed: the question is which. There is no way to identify the occupied drive without looking at both, and assessing costs nothing.
What that changes about the figure he faces: only one recovery is likely needed. Two assessments and one recovery is substantially less than two recoveries.
Why he cannot tell them apart himself: neither will mount. Identifying a drive by its contents requires reading them, which is precisely what has stopped working.
What might identify them without any of that: serial numbers and dates. Purchase records, prior backup logs or the machines they were used with sometimes distinguish them, and that costs nothing to check.
Now the simultaneity, which is the technical finding: two drives do not fail together by chance. Independent failures in the same moment are vanishingly unlikely, so a shared cause is almost certain.
Why his suspicion of a power event fits: it is the commonest shared cause. A surge or supply failure reaches every device connected to it at once.
Why both spinning is genuinely encouraging: the motors and supplies work. Drives that reach rotation have functioning boards sufficient to drive them.
What must not happen meanwhile: no further connection of either. Both are stopping shortly after starting, and each attempt repeats whatever is failing.
On the bench
Content identification was established at assessment before recovery was scoped — determining occupancy requiring only that volume structures be read rather than anything extracted, which is minutes of work against hours of capture, so two assessments and one recovery cost substantially less than recovering both. Simultaneous failure was treated as evidence of a shared cause, independent failures in the same moment being vanishingly unlikely against a supply event reaching both at once.
The outcome
Content identification established before scoping, both drives assessed, and recovery performed on the identified drive. Free assessment, one fixed written figure including VAT, charged per drive, with 50% of parts and labour upfront where a drive has to be opened. The decode: which drive matters is answerable in minutes, not hours. Assessing both costs nothing, and it means paying for one recovery rather than two.
When you cannot tell which of two drives holds the content
Send both for assessment rather than guessing — establishing whether a volume is occupied only requires reading its structures, which is minutes of work, so two assessments and one recovery costs far less than recovering both. Check purchase records, backup logs or which machine each was used with first, since that sometimes distinguishes them at no cost. And treat the simultaneous failure as a finding: two drives don't fail together by chance, so a shared supply event is almost certain.
Have both assessed — call Cambridge Data Recovery on 01223 655015; occupancy established before recovery is scoped, simultaneous failure treated as a shared cause, recovery performed on the identified drive only.
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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.