SD Card and Spinrite

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Apologies for my ignorance, but from following Spinrite information over the years it is my understanding that Spinrite 6 (which I have) cannot access SD cards via USB card readers.

That said, I have a 16gig micro SD card with a strange problem that might be of interest to someone here.

The card has zero value to me, so I am either going to trash it or I will mail it to anyone who might want to look at the problem.

The card is a 16gig micro SD used in a game camera, formatted fat32, and is about 75% full with around 16,000 jpegs.

Using file explorer to delete files and folders appears to work (no error messages) but, when the SD card is re-inserted all original folders and files are sill there.

Both quick and full formatting options in Win10 & Win8.1 complete without errors, but, again, when the card is re-inserted, all original folders and files are sill there.

Same with Chkdsk using /F & /R options

Anyone interested in looking at the card? If so, give me a snailmail address and it's yours, no return necessary ...I would be interested in knowing the "why" if there.

fwiw, life and old age has me swamped at the moment and I don't have time to pursue this on my own.

Beverly Howard

BevHoward.com
 

SeanBZA

Member
Oct 1, 2020
10
0
I will take a guess that this is an older card, and the erase is failed on the cells, so the card cannot erase the blocks to write new data. The reason the format and delete work is because Windows caches the data for the directory, using it instead of the card content to minimise reads to the card. Thus the delete and such appears to work, as the card does not return an error for the write failing most probably, and thus the cached data is the visible one. Remove and reinsert, and you get the original data, though I will guess that some of the blocks of data have very likely been overwritten in the process of the erase voltage multiplier failing, so you will get parts of the images erased, but the FAT and the backup copy could not get erased.

There format appearing to work is that the quick format only writes a new FAT and backup, and then does a quick sanity check using the reported size to see if the reported matches actual, by reading the last block and getting a valid read. Same with full format, the write does not work but the valid data from reading each block is there, no checksum error so format assumes valid, and thus pass, with the new FAT in cache appearing to be valid, but not being written.
 

DiskTuna

Well-known member
Jan 3, 2021
85
8
Netherlands
Yes, common for 'failing' cards. Often firmware decides not to write to NAND after x amount of write/erase cycles, but still allows data to be read and copied. There's not much use in snail-mailing it anywhere.