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Reading data off NAND Flash

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iceblue

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Hi

A friend of mines USB flash drive stopped working recently and it contains extremely important data which forms part of her PHD thesis. The drive shows up when connected but the capacity displays as 0kB. I have confirmed that it is a hardware fault but have not yet isolated the exact component, but based on info I have found on the net, it appears to be the flash drive controller IC which has failed.

My question then is, assuming the controller has failed and the flash is fine, would it be possible to recover the data perhaps by interfacing the flash memory with a mircrocontroller and reading the data off it bit by bit and storing it to a pc? If so, how would you recommend I approach this?

I am an RF and Microwave engineer, so I have experience with digital systems but very limited. I would appreciate any advise on recovering the data as it is very important to her.
 
It is going to be VERY hard to get the data off.

If you think it is the controller IC that has failed, your best bet would be to get a new, identical drive, and either replace the faulty chip on the old opne, or transplant the old NAND flash IC onto the new drive.
 
Thanks, thats actually my plan at the moment (after replacing the oscillator first). Reading the NAND is last on my list, but I am still trying to find an identical drive to get the controller from. So this is just in case I dont find one.

I posted this on another forum as well and was told to rather take it to a data recovery place than take a risk with someones PHD. Just to clarify, it is only a small section of her work which is on it and she is planning to redo it anyway. I am just doing this as a last ditch attempt as she has already been told by someone with data recovery experience that there is no hope for the drive, but all the data recovery places I know of try to recover by software and not at a hardware level which is why I am trying to recover it.
 
It is going to be VERY hard to get the data off.

Can you expound a little on what that would be? I should think it's just a matter of interfacing using data sheet signals and timing, but I never tried before, so I'm sure there is something I"m not thinking about.
 
You're not getting the data back in any useful manner. Data on USB flash drives is not stored in the manner magnetic media is. Due to wear levelling in the controller that's possibly failed you won't know which blocks are physically located where.

This is a good time to school your friend in 3,2,1 backups. Three copies of every file on two different media types (optical, magnetic) where one copy is in a geographically different place (read: tornado, flood, theft, etc.).

Some data recovery businesses do work at the hardware level but I can assure you, you can't afford it. $10,000+ for some repairs. You have to really need the data back.
 
I realise the controller stores info on bad blocks, etc and going around this will obviously lead to problems as you have mentioned. But surely there is way to 'reassemble' everything again once it is recovered? I'm not so much asking for the problem at hand, but more out of interest as this is something I have been trying to lean more about for a while now. Also, each chunk of data (byte, word?) is stored sort of randomly in the memory, is it not? So how does the controller know at which addresses to find all the pieces belonging to a particular file? Again I am asking out of general interest.

As for backing up, I think she has learned her lesson. Although most of the contents of the drive was stored on her laptop, there was some more recent work that she had not yet backed up. In fact she was using the drive when it stopped working.
 
There isn't much I could say that hasn't already been said here -> Presentations & Resources | My Hard Drive Died | Data Recovery and Training

Of particular interest are the following from the above linked site:
**broken link removed**
**broken link removed**

Edit: I would like to add that yes, I do realize that SSDs, rotating hard drives and thumb drives are each different. Some information applies across the board while some doesn't. Pay attention to the parts that do apply.
 
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You're welcome.

Part 5 of this video **broken link removed** starting about 2 minutes in is the section of immediate interest to you. You mentioned wanting to learn about the topic in general though so I don't think you'll mind watching and reading everything else. Enjoy.
 
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