I demonstrate visually the easiest way to recover data from NAND memory of a smartphone, regardless of the reason why you need it. In some cases, the phone is inoperable due to processor damage, flooded circuit board beyond repair, in some cases, the phone is locked, and the data must be saved.
I was lucky enough to work for fix-oscomp, the digital repair division of OSKOMP. Here I got acquainted in practice with this method.
NAND is the type of flash memory most commonly used in today's smartphones.
NAND design according to Wikipedia
The design of NAND is a three-dimensional array. The basis is the same matrix as in NOR, but instead of one transistor at each intersection, a column of series-connected cells is installed. In this design, many gate chains are obtained in one intersection. The packing density can be dramatically increased (after all, only one gate conductor fits one cell in a column), but the algorithm for accessing cells for reading and writing becomes noticeably more complicated. There are also two MOSFETs in each line. The control transistor of the bit line (English bit line select transistor), located between the column of cells and the bit line. And a ground control transistor located in front of the ground (English ground select transistor).
Today's Xiaomi Mi Max 3 patient:
After filling it stopped turning on.
Diagnostics showed that the processor is more dead than alive. The client needs data from the phone and it is possible to restore the device itself.
The board was cleaned, but we cannot replace the processor, since the processor and NAND memory are key-paired and we also change them in pairs. In this case, we take a donor fee from a cheaper model, in this case Xiaomi Redmi Note 5 will do.
We warm up the board with the bottom heating.
We apply flux.
Warm up with a hairdryer.
We remove NAND memory.
Clean up the flux residue.
We check contacts.
Install the memory in the reader.
In our case, we need a userdata section and boot files.
Speed up to 10 MiB/s. But it will take a long time to wait. The reading process takes an average of 2 hours.
Thus, you can increase the amount of memory and RAM if necessary.
We write data to memory from the donor.
We solder the memory and processor from the donor, turn it on and rejoice!
Thank you for attention!
Source: habr.com