There is always a source of corruption. The SD card (or other flash memory device) that has started to display an “unformatted” prompt, empty folder(s), or nonsense file names was corrupted via one of only a few routes. Knowing this route will determine how best to recover data and whether the card is worth using again. First identify the cause, then perform the recovery, and finally repair the card.
The card was pulled out mid-write. It went through multiple devices. It said it had more space than it did. And then the flash memory inside wore out. All of those are going to leave their mark, and if we catch all of them early enough, they don’t have to make you lose your pictures.
Interrupted writes are the most common problem. When a user removes their SD card while the camera’s memory is still being written to (a.k.a., while the camera is saving what was just shot), when the battery dies before finishing a burst of shots, when a phone or tablet reboots in the middle of an auto-save operation... the file system (essentially, the camera’s memory bookkeeping system) gets cut off in the middle of a sentence. On the next photo import into the camera, there is no way to understand what happened and where everything is located. Device-hopping is quieter, i.e., switching from one camera to another, then to a smartphone or other mobile device, etc. Each has its own opinion about how the file structure should be organised, and will continue to add thumbnails and indexes until they begin to contradict each other. Fake capacity is the nastiest, i.e., taking a small chip and modifying it so that it appears to have a greater amount of storage space (such as 256 GB) than it actually does. It will act normally until it reaches its actual limits, and will begin writing over existing files and/or causing total corruption; low-cost memory cards from third-party resellers are commonly used as part of these scams. Finally, plain wear occurs with flash memory due to limited numbers of times that data can be written. Budget-grade memory cards typically utilise the least expensive forms of memory available, resulting in cards that may work fine for years, and then begin forgetting information. Regardless of the method(s) used to lose your photos, recovery is accomplished the same way.
Once you notice some form of corruption occurring on the card, immediately stop using it; every additional write operation will occur over your photos’ last recorded location. Insert the corrupted card into a computer via a card reader (using the camera itself as the cable is slow and unreliable), suppress every option provided by the operating system (format, fix errors, initialise, etc.) since all of these operations require writing to the card, and instead run PhotoRec: free, read-only software that reads data directly from the flash regardless of the state of the original file system, and creates new copies of all recovered files directly onto your hard drive. Create a folder on your computer, direct PhotoRec’s output toward this folder, do not create the folder within the card reader directory tree (since doing so would require additional writes to the card) and evaluate your success based upon viewing the files created by PhotoRec (largest first). Ten minutes of diligence can recover the great majority of lost image files resulting from card corruption without any expense.
This exception skips over the ten minute time period: (a) a non-detectable card; (b) a card which gets warm; (c) a physical rattle. This is hardware failure by the controller or worse, and home tools are unable to hold onto anything; monolith-level reads in the lab can. We begin our memory card recovery service with a free diagnostic for any of these cases.
After photos have been validated as safe on the computer, the card may now be treated fairly. A complete formatting in the device it will live in will rebuild every structure on the card and generally put back into service most cards. However, use the two strikes rule: Corruption that came about with no apparent reason (no ripped out card; no dead battery) typically indicates that the flash itself is failing, and a card that corrupts twice has informed you of its intentions. Cards cost money; reshooting a wedding is impossible. Eliminate the suspect cards, purchase branded products from reputable vendors, format in-device instead of in Windows, and consider each card as a messenger rather than an archive, and transfer your photos off within days. Did you format the card before reading this article, and then recall what was on the card? Same method, same carving technique, dedicated page: formatted media recovery.
No, and flaky behaviour is the exact opposite of healing. If a card only reads on the third attempt, or if it works properly in your camera but not at all in your laptop, this is an indication that either the controller or contacts of the card are failing from repeated attempts. With every retry there’s an opportunity for a partial write to make matters even worse. Use the initial corruption as the card’s resignation letter: remove your photos from the card and then retire the card.
Repeated corruptions will usually have a known cause. The most common causes include the card being moved between two devices which may be treating the card’s file system in different ways; if the card is removed from the device or power is lost during a write operation; or if the card is a counterfeit product where the actual storage capacity is less than what is labelled, causing corruption of all data beyond the real limits; or lastly, the flash memory itself is simply worn out. Cards manufactured by reputable manufacturers, used primarily within one device with proper formatting to that device and removed only after writing has finished, rarely develop habits of repeated corruption.
Not while your images are still intact on the media. If you run a CHKDSK repair on your media, the program will fix the file system by making changes (and unfortunately, in many cases, will convert the damaged image(s) to something called FILE0000.CHK). This has destroyed an entire shoot for several people. The correct sequence is to remove the images from the media using a read-only application, then run a CHKDSK repair or format the media after all of your images have been removed. In this case, it won’t matter what happens to the media.
Typically yes, if you stop using the card as soon as corruption becomes evident. Most logical damage to a memory card results in the card mounting properly but being unable to access the data stored within. Recovery is typically successful. Even physical failures or snapped cards can usually be accessed at the chip level. The only way to destroy photos is to continue taking them on a card that is logically corrupted, or to format it.
We will give you a no-cost 48-hour analysis of the problem here in our lab, as well as tell you whether it would be safe to try and fix it yourself before you put anything at risk.