SD cards stop working for many reasons, including damage, data corruption, and compatibility issues. However, because these cards are designed to be rugged and portable, many data access issues are related to use across many (and in some cases old) hardware platforms, rather than a defect in the card. An SD card is a cross-compatible storage device. However, devices with incompatible file systems make it appear as if the problem is with the card, rather than the underlying devices.

SD cards are theoretically virtually indestructible. These types of storage media tolerate liquid immersion and magnets well. If a card is not working properly, the problem is likely to be a corruption of the file system or an incompatibility between the file system and a particular device or computer.

In many cases, you can regain access to the card with some simple troubleshooting.

Reinsert the card. Removing and reinserting the card, or changing the USB hub to which an SD card reader is connected, often resolves a temporary glitch.