8GB SD card, 1 memorychip is broken, the other not

[ed1973]

I have somebody who step onto her Emtec SD card and broke it.
When I opened the SD card, 1 memory chip was broken into half and the other was not broken.
On that SD card there are very important pictures, she absolutely want to get back.

After doing some research, I found out that the data was striped over the 2 memory chips.

I started to compare it a little bit with a RAID0 (striped) set of 2 hard drives, from which 1 hard drive was missing.

Is it possible to recover part of the pictures, when 50% of the information of the pictures is missing ?
Is it possible to rebuild those pictures ?

[arvika]

It depends on mixes. If client have lucky it will be possible recover some part of data. If for example mixes will be join by byte - there will be no chance.

What controller? Can you post some pictures?

[HaQue]

Just did a SD Card with 1 broken chip.. had join by page in the mix and really there was no recovery. Very minimal files (all corrupt) were recovered and only by thumbnail was there a picture.

SD Cards have mostly mixes that would make it quite low chance.

But do as Arvika says and maybe you are lucky

[pcimage]

Unlikely

[ed1973]

Thanks so far for responding.

I have made a pictures of the SD card , which you can see below:



The pictures have been made with camera Nikon D3000, and an example of a picture size is 249KB with resolution 2048 X 1370 pixels, so I assume the pictures are in jpg format.

[arvika]

This controller use Join by Page 0x200 (one sector) so IMHO recovery will be impossible without one nand.

[ed1973]

Thanks a lot for all the answers. I need to invest further in dept why it is not possible.

Do you maybe have links with information about how it really works. Do you have a starting link for me ?

[labtech]

Thanks a lot for all the answers. I need to invest further in dept why it is not possible.

Do you maybe have links with information about how it really works. Do you have a starting link for me ?

Use the search function for keywords or can read the flash part of the forum. Plenty of info.
You will not find specific info about your chip config and solutions like a story book or "NAND Recovery for Dummies" series edition. That's not how it works.

To truly find out on your own, the solution is to buy another device like it, ideally the same, dump some data on it, build ur own rig or spend a couple of thousand $$ for a NAND reader and software, and then start working and investigating. Prepare to spend quite a bit of time learning.

[HaQue]

a VERY simplistic view of what is going on. Bear in mind after the Join by page 0x200 there is other mixes applied, making it even more disastrous.

You cannot be missing half the DATA.

In SOME chips, data is not mixed, or mixed between the chips making it possible to retrieve some files. But even then it is not easy work.

[ed1973]

I have two Teensy++ 2.0 USB Development Boards , to read out NAND and NOR chips from ps3 game consoles, can that one be used to read out the chip ?

I am going to learn lots more about in, the coming period. Need to make an image of the data stored on the NAND first.

[HaQue]

Possibly, but best idea is to contact a DR firm near you and ask them to read the chip for you. This alone should not cost much, I would probably do it, copy it to a 8GB USB and give it to you for $20. BTW that offer stands if you wanted to post it here..

Then you could have the dump.. but you would also need to figure out the ECC and XOR schemes, as the data almost certainly is not sitting on the chip in any useful form right now.

To see difficulty:
[url][/http://h30499.www3.hp.com/t5/HP-Security-Research-Blog/Reverse-Engineering-NAND-Flash-Memory-POS-device-case-study-part/ba-p/6581528#.VJkbAZDAAurl]

There was also another one I cant find right now, but it is my posts somewhere about figuring out an SD Card

[HaQue]

here is another link to reading nands if you are really wanting to go commando: http://hackaday.com/2012/09/20/reading-bare-nand-flash-chips-with-a-microcontroller/

[ed1973]

I conclude that recovering parts of the JPG pictures, which were stored on the SD card, is very very difficult.

Actually it consist of 2 parts:

1) Make an image of the memory chip
2) Figure out, how the data is spread over the memory chips and merge them together

It is easy for me to desolder the memory chip and also my soldering skills are pretty good I think. I made a video about it, which you can see here : https://www.youtube.com/watch?v=jf3Wzo-HP4U

@HaQue : Can you make a dump of the memory chip when I send it to you ?
I am located in The Netherlands, what do you charge totally when you do it ?

[HaQue]

Sure I will, I won't charge you, I think if you pay for shipping here, I will send it back with dumps. Probably be able to help you see recovery chances as well. Just PM me for details

[ed1973]

@HaQue : Justed PM'ed you, sorry for the late response.