EMMC unit gives up its secrets

A growing phenomenon over the years since cell phones have gone from mere phones to general purpose pocket computers has been the phenomenon of a dead device that takes some precious digital resources with it. In most cases, this means that the device is dead, but it does not necessarily mean that the data is completely gone. Inside the device will be an eMMC flash chip, and if that can be read, then the data is safe. This also applies to some single-board computers, so [Jeffmakes]” Adventures in recovering eMMC from a dead Raspberry Pi CM4 Particularly interesting.

The whole thing depends on the eMMC offering the same interface as the SD card, so while it comes in a multi-pin BGA package, it can be tackled with surprisingly few wires. Using a PCB from another dead CM4, it traced the relevant connections from the eMMC to the SoC platforms and thus was able to make some very fine welds to create the interface for the SD card reader. The entire disk can then be imaged.

This work will be of great use to experimenters who have experimented with their computing units, but of course the information it contains will also be useful for retrieving those photos from the phone that fell into the bathroom. This isn’t the first time we’ve taken a look at someone’s efforts in this field.