SD flash memory cards are convenient for portable data storage and data transfer from one computer to another. Unfortunately, these cards can sometimes be damaged and require repair. All the instructions here https://www.salvagedata.com/ will successfully repair all SD cards, except those that are physically or electronically damaged.
How to Repair a Corrupted SD Card
SD Card Type
Determine the type of SD card you have. If it is 2GB or less then it is a standard SD card. If it is 4GB or more then it is an SDHC or high capacity card. (There are some standard 4GB SD cards, but most are SDHC.) If it is larger than 32GB then it is an SDXC or Extended Capacity card.
An SDHC reader is required to read high capacity SDHC or SDXC cards as the memory allocation format is different. If your data is on an SDHC or SDXC card, it may be intact, but you will need the SDHC device to read it. Some devices, such as readers and cameras, may have software downloads available to update the device to read SDHC or SDXC cards. Go to the device manufacturer’s website to determine if such an update is available.
Reading the SD Card
Insert your SD card into the card reader. If no drive letter is assigned to it, the computer is not reading it. In some cases, the reader may be assigned a drive letter, but when you click on it, the message “Please insert disk in drive E:” appears, indicating that it is not reading the card.
Sometimes a particular device may not read an SD card, while other devices can. If you don’t have another device, ask a friend to try reading your card.
Damaged SD Card Repair
You may find that your computer accesses the card, but does not read the files on it. Try several different files on the card. If some of them read and some of them don’t, then one or more files may be corrupted. There are numerous file recovery programs available; some of them are free. If certain vital parts of the file are damaged, it cannot be recovered.
Sometimes scanning the SD card will fix things. Usually it won’t fix a faulty file, but it may be worth a try. To do this in Windows 7, locate the card in “My Computer” or Windows Explorer “and right-click on it. In the pop-up menu, click on »Properties«. A new window displaying a pie chart shows the available disk space. Select the “Tools” tab, then click the “Error checking” button. Click the checkbox to fix the file system errors and click the “Start” button. The process should only take a few seconds.
To do this in Windows 8/10, locate the card in the “This PC” section of Windows Explorer and right-click on it. In the pop-up menu, click on “Properties”, then on “Tools” and click on the “Verify” button. Once the errors are found, click the “Repair Drive” button.
Unreadable Files and Recovery Programs
In some cases, none of the files can be read. Sometimes the directory will display the file names, but the files cannot be accessed. In other cases, the file names are junk characters or may not appear at all. Right-click on the drive letter and select “Properties.” The pie chart will show the space used on the card. If it shows all or most of the free space, it means that the files have been deleted or the directory has been deleted. In this case, a file recovery or restoration program can help (but don’t count on it).
SD Cards Locked
If your card reads fine but you cannot save a file, the card may be write-protected. On the edge of the card is a small slide switch that is usually labeled ‘Lock’. If this switch is slid away from the connector end of the card, then it is “locked” or write-protected. To save or modify files on the card, the switch must be in the unlocked position or toward the connector end of the card.
Completely Lost Files
If you still can’t read or write to the card, your files have probably been lost. There are some disk diagnostic tools available, but some of them do not work on memory cards. If you’ve been resigned to losing your files, you can still use the card by reformatting it. To do this, right-click on the drive letter and select the format. This will erase everything on the card, so make sure you’ve copied everything you can to another drive. When the card is reformatted, the directory structure is recreated, so you should now have full access to the card. If the card still doesn’t work, it’s time to discard it. Also Check: h2testw