The mystery of my micro SD card (new one required)

[unplanned bacon]

Class 10 64 GB SanDisk in a Galaxy S4
Back in 2014 it went read only for some reason. Apps still seem to be able to write to it when they have to, but if I need to write to it it fails. That means my music can't be modified and is way out of date. I can't get my pictures off (I can copy but not delete). I tried formatting it, my Mac says it's all done, and so does my phone when in reality it's had no effect. It's the same when copying to or deleting from it (says it's all fine and done, but it's actually had no effect)

What happened!? One day it was fine and the next it was doing this and all pictures being written to it by the camera were going corrupt. I tried to copy a simple text document that hello to it and it got corrupted into gibberish and then deleted

EDIT: Just seen they're going dirt cheap unlike what they cost 2 years ago. What's a good one to go with for the S4?
This one maybe? https://www.amazon.co.uk/Samsung-MicroSDXC-UHS-I-Memory-Adapter/dp/B00J29FF4G/ref=sr_1_3?ie=UTF8&qid=1463879942&sr=8-3&keywords=64GB+micro+SD+card

 

[Mr5oh]

Usually when this happens the SD card has gone bad. SD Cards have a limited number of read/writes. Get any data off of it you can now, and order a replacement now. Physically destroy (break) your old card when your replacement comes in. As for brand, its just been pot luck for me. Definitely stick to class 10 though.

 

[ak47jar3d]

Make sure you ALWAYS format cards to FAT32. Most issues most people encounter with sd cards and phones are because of the file system being exfat.

 

[Solandri]

Class 10 64 GB SanDisk in a Galaxy S4

I have the same card. Sandisk seems to have gotten a bad batch of flash memory about the time these were made. What you're describing (can read but can't write) seems to be a common failure of this particular model. I just RMA'ed mine and they're sending me a replacement.

http://forums.sandisk.com/t5/Mobile-memory-professional-cards/FORMAT-64GB-MICRO-SDXC-PROBLEM/td-p/293517

http://kb.sandisk.com/app/rmaform

 

[unplanned bacon]

Class 10 64 GB SanDisk in a Galaxy S4

I have the same card. Sandisk seems to have gotten a bad batch of flash memory about the time these were made. What you're describing (can read but can't write) seems to be a common failure of this particular model. I just RMA'ed mine and they're sending me a replacement.

http://forums.sandisk.com/t5/Mobile-memory-professional-cards/FORMAT-64GB-MICRO-SDXC-PROBLEM/td-p/293517

http://kb.sandisk.com/app/rmaform

I'll be trying the Samsung later this week. Could the SanDisk have been the cause of my phone's erratic behaviour?