A school’s external Samsung NVMe drive had been crashing during use for weeks, always after it had been running a while. Eventually it stopped being detected at all — with exam records, student data and the administrative database on it.
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A school used an external Samsung NVMe drive for administrative storage — GCSE student records and exam data, the school database, class schedules, reports and spreadsheets. It had been crashing intermittently for some weeks, always after a period of sustained use, and had latterly stopped being recognised altogether.
The material included personal data on minors, which changes the handling requirements before any technical question is reached.
crashes after sustained use, recovery after cooling, then eventual total failure — that sequence describes thermal stress on the controller rather than flash exhaustion.
discolouration around the controller package, consistent with prolonged operation at temperature rather than a single event.
which is the usual pattern. Heat degrades the controller and its solder joints well before it damages the flash it manages.
a compact external case with no meaningful thermal path, running a drive designed to sit against a motherboard heatsink.
External NVMe enclosures are where this fault concentrates. An M.2 drive inside a laptop or desktop at least has airflow and often a heatsink; sealed inside a small aluminium or plastic case with a USB bridge, it has neither, and sustained transfers push it well past where it throttles.
The drive was removed from its enclosure and reached at controller level in vendor-specific diagnostic mode, which allowed the service area and translation tables to be read directly — the mapping without which the flash is undifferentiated data.
It was unstable when warm, so imaging ran in short passes with active cooling and rest intervals between them: the same fault that caused the failure limits how it can be read. Regions returning inconsistent data were re-read until they settled rather than accepted on a first pass. Nothing was written to the drive at any stage.
Everything. The controller had failed while the NAND remained sound, which is the usual outcome of thermal damage and the reason these recover as well as they do.
The school database was checked for structural consistency rather than merely copied — a database file that is byte-complete can still refuse to attach — and records were confirmed readable in the software that needed them before the set was returned on fresh media.
Because the data included personal information about pupils, the work ran under a signed data processing agreement with a single named contact, all data remaining in the UK, and working copies destroyed on an agreed schedule.
An external NVMe enclosure is a thermal compromise. The drive inside was designed to shed heat into a motherboard and a heatsink; in a sealed case it has neither, and sustained transfers take it past the point where it throttles to protect itself. Crashes that happen only after a period of use, and clear up after the device cools, are the warning — and they are easy to blame on the computer instead.
If a portable drive holds the only copy of anything, it should not. SSD and NVMe recovery is from £300 +VAT after a free 48-hour diagnostic, and where the data includes personal or regulated records we sign a data processing agreement as standard.
Bring the drive to our Oxford Science Park reception, or post it over — it costs nothing to learn what went wrong. You’ll have a written figure from the fixed bands before any work begins.