A volunteer running trail cameras for a deer survey in Bracknell Forest left a card in a cheap USB reader overnight. By morning the reader was hot enough to be unpleasant to hold and the card had split across its middle, one half still in the slot. Eleven weeks of overnight footage from four camera positions were on it, and the survey window had closed.
| Media | A full-size SD card that overheated in a USB reader and cracked into two pieces. It holds eleven weeks of overnight trail-camera footage from a wildlife survey. |
| What was reported | SD card, became very hot in a card reader, cracked into two pieces, holds several weeks of survey footage that cannot be re-recorded, recovery wanted. |
| Fault class | Physical damage to the card body, caused by heat. The card had split, but the break ran through the plastic and the trace area rather than through the memory die, so the storage itself had survived and could be reached directly. |
| On the bench | Both fragments examined under a stereo microscope and the break mapped against the position of the die, the memory read at chip level with the die freed from the remaining card body under hot air and read on a specialist programmer, the raw dump descrambled and its page layout reconstructed, the volume parsed in R-Studio, video files carved by content signature, each clip played through before being written to fresh media. |
An SD card is mostly plastic, and the plastic is not the important part. Inside is a small memory die and a controller, moulded into a body that exists to hold a shape and meet a set of contacts. When a card breaks, what matters is whether the break passed through the die or merely through the packaging around it.
Heat in a reader is a reader fault more often than a card fault. A card that gets hot enough to distort has usually been fed too much current by a badly made reader, or has been sitting in one that never stopped drawing. The card is the casualty rather than the cause, which is worth knowing before buying a replacement of the same type.
The position of the crack decides everything. A break across the contact end or the label end usually leaves the die whole. A break through the middle of the die itself ends the job, because there is no repairing a fractured piece of silicon and no reading half of one. That assessment is done under magnification before any figure is quoted.
Reading a broken card means reading the memory, not the card. There is no repairing the body to the point where it can be put in a slot again. The die is freed from what is left of the packaging and read directly, and the structure the controller used to impose has to be worked out afterwards from the dump.
Both halves arrived in a small bag, which was the right way to send them. Under the microscope the break was mapped against the die: it ran through the moulding and clipped the trace fan-out, missing the die itself, which meant the job was viable and could be quoted.
The die was freed from the remaining body under hot air and read on a specialist programmer, producing a raw dump with no usable order to it. The page layout and interleaving were reconstructed, the scrambling reversed, and a coherent image assembled. R-Studio found the volume badly damaged by the break in the trace area, so the clips were carved by content signature instead, and every one of them was played through before it was written to fresh media.
All four camera positions came back, with a handful of clips truncated at the point the card had failed and the rest complete. The survey window was met. The card did not come home in a usable state, because it cannot: what was recovered came off the die rather than out of the card.
Cards and USB sticks are £250 + VAT. Chip-level work is one of the categories the published exclusion names, so the guarantee did not run here: 50% was payable before the die came out and the balance after the footage had been checked.
Keep every piece, including the fragments that look like nothing. Put them in a small bag rather than loose in an envelope, because the pieces grinding against each other in the post can do more harm than the original break. Do not try to tape the halves together and force them into a slot: a partial contact can put current through a damaged trace and take the die with it. If a reader has been getting hot, stop using that reader on anything else, since the next card will fare the same. Whether the break missed the memory is the whole question, and it takes a look under magnification to answer it.
These files are written up from genuine enquiries taken from households and businesses in Bracknell, across Berkshire and Surrey and into London, with names, firms and anything else identifying stripped out. Each one sets down how the fault was reasoned through, the method it actually needed and the equipment it was worked on. One of them is a job that was turned away, which belongs here as much as the rest of them.
A format prompt is the machine admitting it cannot read the index, not an instruction to obey
Corrupted details followed by no recognition at all is a controller failing in two stages
A snapped-off connector stops a stick plugging in, and says nothing about the memory behind it
Examining it is free and takes 2 working days from arrival, the figure goes to you in writing and does not move afterwards, and a logical fault carries no fix, no fee. Start online or ring the freephone.