Missing or corrupt files · job record · NTG-2025-1461
Every Large Copy Stopped on the Same Three Words.
For years it had sat in a dock on an office shelf. Then the electricity went off, and from that day nothing would copy through cleanly — individual files to begin with, then whole folders, always halting on three words: cyclic redundancy check
. Another lead achieved nothing. Nor did taking it down to the works and putting it on the laptop. Nor did two attempts at a repair: Windows checked it two nights in a row and neither time did it reach the end
. Thirty years of shop drawings were on there, the whole working life of a metal fabricator on Colwick Industrial Estate in Nottingham — every staircase and every handrail I have built since I started
.
Yours doing the same? Say what it is up to — looking is free.
0115 8220606
What went wrong, and why.
Far more gets read into that message than it actually carries. One thing is reported and nothing else: the data returned by the drive did not match the checksum held against it. The identical wording covers two faults with nothing in common — bookkeeping that has drifted on hardware in fine health, or a surface no longer able to hold what was put on it. Treat the second as though it were the first and you will make it worse, which is where guessing turns expensive. Put a weak patch in front of Windows and it responds by asking again, and again, and it will not stop until the sector replies or the drive falls silent. Two nights had already gone that way.
The bench work this one took.
How the work runs →| Kit on the bench | What it did on this job | Why we reach for it |
|---|---|---|
| DeepSpar Disk Imager 4 | Imaged with a retry ceiling, poor ground logged and stepped over | One platter side per pass, with the heads mapped before a single sector is taken off, and the resets, the timeouts and the power all held under our control |
| R-Studio Technician | Volume rebuilt off the copy, not off the drive | Rebuilds an array off the images, and reads almost any file system |
| ACE Lab PC-3000 Express | Questioned the firmware before touching a sector: attribute trends, grown defect list, two overnight sessions on record | Reaches the maker's own service mode, which standard ATA commands cannot |
What happened on the bench.
The drive keeps records of its own, so start by asking it
Before any imaging the firmware was interrogated, and its answers were unambiguous. Reallocated sectors were high already and rising, with more waiting their turn behind them. The power-on log carried two long sessions that lined up, near enough hour for hour, with the nights he had spent scanning. Surface, then — not bookkeeping.
Put a ceiling on retries, because retries are hours
Limits were settled before a sector moved: brief timeouts, a fixed number of attempts, and any band that pushed back written down, stepped over and left alone. Right at the end those skipped bands got one short run each. That is arithmetic rather than obstinacy. Spend an hour on a single bad sector and you can lose the thousand good ones behind it.
Switch the disk off; work on the copy
The Toshiba was powered down the moment its copy was safely written, and it stayed down. The result was better than the counters had suggested it would be. Every part of the folder tree was present, and what could not be read had gathered into one band under a single run of scanned sheets. Each of those sheets is named in the report under its own filename, which gives him a list for the plan chest instead of an apology.
What was returned.
One folder had been named on the telephone as the one to do first: staircases and balustrades in buildings the public walks through every day. It was opened and read before any invoice was raised. A new disk carried the archive back, complete but for the sheets the report lists. Paper prints of two survive at the works, so those can be drawn out again. The others came from jobs that were finished before he took the firm on. That paper went a long time ago.
Start here if the same thing is happening to yours.
Other jobs about missing files and unreadable volumes.
Sounds like yours? Switch it off before anything else.
£250 + VAT covers a card or a USB stick; a single drive is £300 + VAT; RAID and NAS start from £500 + VAT. Nothing is charged for the first look, and a fixed figure reaches you in writing before any chargeable work begins. Switch the device off, leave it alone, and post it in. On most jobs, no data back means no fee.