SD card stopped working on Android device

Maybe the SD card slot on the phone is damaged or the solder has failed (dry joints) and contact has been lost on one or more contacts.

 

what phone do you have? have you tried other sd cards?

 

I had a similar problem when the sd card was not formatted correctly. I had to buy a new one and unfortunately I couldn't get all the data back.

 

I got a Galaxy S5 that actually destroys any SD card you place into it. I probably went through 3 before I discovered that. They'd all say 'SD CARD CORRUPT' (when they read fine in another device) and try formatting it just sits at 'formatting SD Card' forever. Take it out of the S5, try to use it in say a PC, it doesn't even know it's there. Any other phone just acts like it's not there either. Won't detect or read anymore. I stopped using SD cards in the S5 for that reason. Never figured out what caused it though.

Many modern Android phones will display a notification saying 'there's a problem with your SD card' and it sets it to read-only. This usually happens because the write-limit has been reached for the SD Card. They have a finite set of writes before they won't allow you to add any more, even if storage is available. That's why I don't trust SSDs in PCs. I doubt highly any SSD will outlive that Western Digital Caviar 80GB that's still working on my HP Pavilion PC from 2003.