Data Recovery Case File · Cameras, Drones & Cards · A Cache That Outlived Its Originals
The Phone's Own Thumbnails Prove the Photographs Existed and Say Where to Look
Her enquiry contains a find that is worth more than it appears. Photographs missing from a phone with a card that has stopped working, where "I have discovered them in thumbnail versions in a thumbnail folder on my phone, but not the full images" — and she removed the card as soon as she noticed. Those thumbnails are the phone's own cache, stored separately from the originals, and they establish two useful things at once.
| Media | Memory card removed from a phone after content loss — card no longer functioning; corresponding thumbnail cache surviving in the phone's internal storage |
| Reported situation | Photographs discovered missing from a phone · memory card in the phone having stopped working · uncertainty as to whether images were held on the card or in phone storage · thumbnail versions located in a cache folder on the phone · full images not present · card removed from the phone promptly on discovery |
| Fault class | Content loss with a surviving thumbnail cache — cache confirming prior existence and providing a manifest; originals to be recovered from the card or from phone free space |
| Equipment used | Thumbnail cache treated as a manifest and as evidence of prior existence · card removal credited as preservation · card addressed through hardware with imposed timeouts rather than the host stack · phone storage examined separately for original content in unallocated regions · recovered images reconciled against the cache |
The decode: what a thumbnail cache is, and how it helps twice
Where those thumbnails came from: the phone made them. A gallery generates small previews so it can display grids quickly, and stores them in its own internal cache — separate files, in a separate place, generally in the phone's own storage rather than on a card.
Why that explains their survival: they are not part of the photographs. Whatever happened to the originals did not happen to the cache, because the two live in different locations — which is why she can see one and not the other.
What that immediately establishes: the photographs existed on this phone. A cache entry is only created from an image the gallery has seen, so their presence is direct evidence rather than recollection — useful when she is unsure whether the images were ever on the card at all.
How it helps a second time, and this is the practical part: the cache is a manifest. It records how many images there were, roughly what they were of, and their dates — which gives a target to recover against and a way to tell when a recovery is complete.
Why the thumbnails are not a substitute: they are small, heavily compressed and made for display. A preview cannot be enlarged into the photograph it came from, because the detail was discarded when it was created — so they are evidence and a manifest rather than a fallback.
Why they are still worth keeping: if the originals cannot be recovered, the thumbnails are what remains. They should be copied off the phone and kept regardless of the outcome, since the cache can be cleared by the phone at any time without warning.
Why her uncertainty about location is resolvable: the cache being on the phone does not indicate where the originals were. A gallery caches everything it displays, from card and internal storage alike — so both need examining.
Why removing the card promptly was the right move: a phone writes constantly. Leaving a card in a working phone means anything deleted on it is being displaced, and she stopped that at the earliest point she could.
Why the phone itself now needs the same treatment: if the originals were in internal storage, they are in space the phone is still writing to. The card is safe and the phone is not, which reverses the usual urgency.
What must not happen: no clearing the cache, no gallery cleanup, and as little use of the phone as possible. The one thing that proves what she lost is the thing a maintenance routine would delete.
On the bench
The thumbnail cache was treated as a manifest and as evidence of prior existence — galleries generating small previews for display and storing them as separate files in internal storage, so the cache survives events affecting originals held elsewhere, and an entry exists only for an image the gallery has seen. Previews are compressed for display and cannot be enlarged to originals. Card removal was credited as preservation, and phone storage examined separately for original content in unallocated regions.
The outcome
The cache treated as manifest and evidence, card removal credited as preservation, and phone storage examined separately. Free assessment, one fixed written figure including VAT; on cards and phones where content has been deleted, the figure is payable upfront. The decode: those thumbnails are the phone's own cache, stored separately from the photographs. They prove the images existed on this device and tell us how many to look for — but they cannot be enlarged back, because the detail was discarded when they were made.
Finding thumbnails when the photographs have gone
Copy the thumbnails off the phone now and don't clear the cache or run any gallery cleanup — the one thing proving what you lost is exactly what a maintenance routine deletes. They're worth having for two reasons: a cache entry only exists for an image the gallery actually saw, so they're evidence the photographs were on that device, and they act as a manifest telling you how many to look for. They aren't a fallback, though, since a preview can't be enlarged back into the original. Removing the card promptly was right — but the phone is now the urgent one, since it keeps writing.
Copy them off and stop using the phone — call Easy Data Recovery on 028 9002 0144; cache treated as manifest and evidence, card addressed through hardware, phone storage examined separately.
Request a quote online →
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.