I am stuck with the same problem. My Micro SD threw up on me , when one slightly “fat” sized MicroSD adapter, go stuck in a built in Laptop SD card reader and I had to use clippers to get it out. The adatper had scratches on it but the microsd should have worked. Now it shows 8mb instead of 4gb
There has to be some BLOCK level formatting utility that wipes clean the data.
How about Fdisk in linux or gtparted. Could someone post their exp with those.
THanks
Sam