To reinforce what other members have already said:
mabel_photo wrote:
HaQue wrote:
Do you know what formatting is? It is writing a new BLANK file system so the card is ready to store files.
Not totally true. You are refering to a full format.
Sorry, but you are wrong - even a quick format does write a new blank
filesystem (as
HaQue said), but does not erase the data, as you later agreed. It is that overwriting of filesystem metadata (i.e. FAT tables, in the case of a FAT-formatted card) which causes problems with later recovery, especially of fragmented files or unusual file types, for the reasons which
fzabkar has explained.
mabel_photo wrote:
I've watched loads of videos and read on various forums that the first step in data recovery from an SD card or Memory stick is to try and format the drive.
I've seen them too and those forums / videos are
wrong. That is absolutely
not the "first step" except for those who, through lack of research, understanding & experience, do not realise what they are destroying.

Interestingly, some time ago, I found one specific situation where quick-formatting a card would
appear to help for Windows (and only Windows) - it's interesting, but too long a story for now. The point is that, as we keep saying on here, recovering under Windows has limitations, and if someone had quick-formatted the heavily-fragmented card I was recovering, the result would have been a disaster for subsequent recovery (which I confirmed as a test, by doing the quick format
after I had
successfully recovered the photo & videos using other methods, and then trying to recover files from the the quick-formatted card; not good).
mabel_photo wrote:
My plan is to remove the NAND flash and try it on another SD card, or change out the controller.
My guess is there is something wrong with the controller.
You're likely to be wasting your time, although you
might be lucky, depending on exactly what you do. However if your guess is wrong, you may lose your customer's data
permanently - this is not a risk-free "try X and if that doesn't work then try Y" situation. Such guesses and risks are not the way that I would want you to proceed, if I was your customer. However if you have already decided what to do, and aren't listening to the advice from here (which you asked for!), then it seems we're done. What a shame.
