MicroSD cards are monolithic memories: all components are fused and integrated into the plastic. This makes them waterproof but very difficult to recover if they break.
Controller Failure vs. Memory Failure
The most common scenario is the internal controller burning out or its firmware becoming corrupted. When this happens, the card appears dead or shows 0MB.
To recover the data, a technique called "Spider Web" or direct soldering to hidden test points (pinout) on the back of the card is used. This allows for reading the raw NAND memory (dump) and then reconstructing the file structure using specialized software that emulates the original controller algorithm.
