Lets Study Pen Drives [ USB Flash Disc's ]

Hi Mates ,
These Days Lots of Customers Are Coming With Thier Pen Drives For Data Recovery .Doing Logical [Software Based ] Recovery is Fine .But Lets share Info With Each Other When The Issue Is Actually The Electronics In The Drives .Are We Open To discussions On This Issue .I Had a Very Good Experience From 1 Pen Drive Today And Would Like To Share The Same IF You Feel We Need To Actually Talk On This Subject

Hi Amarbir,

I'm struggling with flash cards now, but i think the problem is about the same.
I've got the data from the flash eprom, but now i have to find out how the pictures are stored, and write some software to retrieve them.

I am searching for datasheets for the memory-controllers of flash disks and usb sticks, which would be a great help, but i can't find any.

Any help on this topic is welcome.

Best regards,

Dobre

Yes, i have two here I'm struggling with.

One is where the USB connector is ripped off and looks like damage the USB controller. On this one I think to transfer Flash RAM to donor USB stick, but need to confirm how to do this.

Another is seen as a device but 0 bytes. Last time I had one like this, there was loose connection on Flash RAM chip. a quick blast with Hot Air Gun, and was OK. This one is not the case. Do we think Flash RAM chip is cooked?

Cheers

Any input gratefully received!

Sean

Hi Sean,

Transferring the ram to another stick is not always a good idea since rams tend to get corrupted blocks and the controller then ignores them and uses a spart block of the ram, and also the memory is not addressed in a contiguous way since the controller tries to do a balancing of the write load so that every block of the memory is written to an equal times.

This info is stored in the controller. Therefore i would like to get the datasheets so i can study how they do it and where this info is stored (normally in the controller i guess).

Lots of work to do before we will have a solution to this.

Best regards,

Dobre

Dobre, I was thinking to put RMA chip on a USB stick with the same controller.

Surely the controller must store its info on the Flash RAM, as the controlller itself cannot store anything?

Just my thoughts ;-)

Thats why i need the datasheet! I've allready worked with many microcontrollers and it is not uncommon they have a small EEprom memory onboard.

Btw; how to resolder BGA's ? Are there any tutorials on the net ?

Regards,

Dobre

Hi Dobre,
I Got a Pen Drive From a Customer Yesterday And This is What I Did

1 :The Drive Was Totally Dead
2 :I Tinkered With The Electronics And Figured Out That Voltage To The Crystal Was Comming But there Was No Frequency Generation
3 :I changed the Crystal And The Pen Drive MCU started To Tick
4 :The Drive Was Still Not Functioning OK
5 :I Soldered The Drive
6 :Tested Worked differently
7 :I again Soldered [ Worked Still Differently ]
8 :After Soldering The third Time [ It Worked Perfectly ]

Conslusion

1 :check The Crystal Always
2 :Very Imp Soldering Should Be Correct [ These Chinese Pen Drives Are Like Very Bad In This

Thanks for the explanation Amarbir.

In many cases the solerings of the ram are bad.

Recently i got a flash card that was broken in two pieces, just between the controller and the flash ram.
:shock:

I tried to reconnect all traces but that was very difficult since some cracks were under the flash.
Finally i had to give up.

So i would like to have (write) a program that can reconstruct the data from the binary read-out of the flash.
Not so easy i'm afraid.

Dobre

Dobre,
This is Were I Would Like The Experts To Step In ,Anyone Having a Hardware And Software Solution So That We Can Take The Memory Chip Out Read The Memory And Then Analyse The Same And Extract The Data .I Think The FAT ,FAT32 or The NTFS Should Not Have Anything To Do With This

Amarbir

Just my quick guess, as I had mostly mechanically damaged sticks on which transplanting the Flash chip(s) to equal pcbs cured the problem:
has anyone yet checked whether the data is simply written linearily like on a LBA hard disk device and can therefore be recovered by any FAT32/NTFS/... data recovery software that is able to deal with image files of raw devices?

Hi,

many times I found the voltage regulator is burnt in pendrives. This is easy.
Crystal is another source of problem.
Up till now I have'nt had problem with soldering.
I had some SD and CF cards I had to desolder the memories, read out, analize the contents and write prog to assemble the image. This is not an easy work, and many times the data is not that important it would worth the costs.
But. I know the factories have utils to access damaged medias and restore them, at least SanDisk states this in the manual of my CF card.
So it is one way to talk to them to give some info or SW, maybe with a non-disclosure agreement.
But I am afraid this could be as expensive as writing my own SW, which I know how works and work (hopefully) exactly the same way I want...

regards,
pepe

Hi Pepe,
How Is The Data In The Flash Memory Stored

1 :Is This Like In The HDD [ So That We Can Make a Image And The Image HAs All The Partition Table Fat Copy Dir Area and The Data Area

2 :I Think Burnt Regulator Should Lead To Flash And MCU Damage

3 :Crystal Damage Is Easy To Rectify

4 :Some Software Are Available On The Net For Doing Specialise Things To The USB Memory Sticks

5 :A Software That Could Read The Data From Many Known Flash Memory IC And Then Write The Same In Some Other Capacity/Type IC And Do The Change On the Fly .Then We Could Put That Flash Ram In Some Donor MCU and Make It Work .

Come On Guys Kets Keep The Pressure Up On Our Brains ,Its Long Time Since i Left Programming ,I Was a system Programmer Writing Antivirus Softwares At My Schooling Days .Now I Have To Learn a Lot From You Guys With ISA And PCI PC3k

Hi Maysoft ,
Thanks For a Seprate Forum For This One Really Apriciate This From You .Keep Up The Good Work I Like That Very Much And I Am Waiting For Guys TO Come Up On This Subject

Hi Guys Lets Start sharing Datasheets of MCU ,Memory And Regulators

OK,
Just Spend Some Time On Google And Few Ideas Are Up My Mind

1 :Making a Nand Flash Memory Reader/Writer Would Be Easy By Using Any Nand Flash Reading MCU Like Onspec ,Ali Etc .More Info On http://www.hjreggel.net/cardspeed/info-controller.html

2 :We Could Use Adapters With even Zif Socket For Reading The Memory Like What Willem Epron Programmer From Sivava Has http://www.sivava.com/Adapter.htm

3 :Use Any Excellent Data Recovery Software What Recongnises The Connected MCU And Do Data Recoevery

4 :I Am Currently Designing Such Kind of Device And Would Like To Share The Design With Fellow Friends Here On The Website

Cheers

Hi Mates,
Any Comments

Amarbir

Hi Mod,
Please Delete This thread AS Not Its In The New Forum You Created ,Creates Confusion ,This is a Request

PS

elete From This Forum Only

Amarbir
There is only one topic. Previous forum has just a link to the topic, not another copy.

Hi Maysoft,
Thanks on The Explanation .Today i Also Discovered New Things About Flash Recovery ,Just Feeling Very Tired Will Post Tommorow .This Is a NAND Flash Reader + Writer With TSOP Socket

Hi Amarbir,

I'm for the moment busy with analysing the memory contents of some flash cards. This will take some time i'm afraid.
What I can say already, is that from what i've seen by now, the data is NOT written like on a harddisk. It is completely different.

Best regards,

Dobre

Hi Man,
Still Waiting For Your Analyses

Amarbir