NAND flash and chip-off data recovery

What NAND flash is and where it lives

NAND flash is the memory inside almost every modern storage device: USB sticks, SD and microSD cards, SSDs, phones, tablets, dash cams, drones, voice recorders, game consoles and the control units in vehicles and machinery. It stores data as electrical charge in billions of tiny cells.

SLC, MLC, TLC and QLC

The number of bits stored in each cell: one, two, three or four. More bits per cell means more capacity for the money and less tolerance for wear and time.

3D NAND

Current chips stack cells vertically, with well over 200 layers in recent generations. Capacity per chip has grown enormously and so has the error correction needed to read it back.

eMMC and UFS

A NAND chip and its controller in one soldered package. eMMC is found in older phones, budget laptops, tablets and embedded devices. UFS is its faster replacement in current phones and thin laptops.

Monolithic devices

Controller and memory sealed in one block with no separate chip. All microSD cards and most slim USB sticks.

Why reading a chip is only the start

A NAND chip never holds your files in order. The controller scatters data across the chip to spread wear, keeps spare copies, marks bad blocks, scrambles the bit pattern and adds error-correction codes to every page. After a chip is read, all of that has to be undone before a single photo or document appears.

Our methods

1. Controller-level access. Where the controller still responds, we put it into its factory diagnostic mode and repair or rebuild the translation tables. The data comes out already decoded. This is the main route for modern SSDs.
2. Chip-off. The NAND chip is removed from the board with controlled heat, cleaned and read in a dedicated reader. We correct bit errors with repeated tuned reads, then reverse the scrambling, page layout and block order to assemble a working image.
3. Monolith recovery. For microSD cards and one-piece USB sticks we remove the protective coating, find the technological contacts and connect to them with hair-thin wires under a microscope. The memory is then read as in chip-off.
4. Direct eMMC and UFS reads. These chips can often be read in place through test points on the board, without removing them, or removed and read in an adapter.
5. File system rebuild. The image is turned back into folders and files, and damaged video, photos and databases are repaired where possible.

When chip-off will not work

This applies to every current iPhone and iPad, Android phones from roughly 2017 onward, Macs with a T2 chip or Apple silicon, and most current NVMe SSDs. For these the right approach is to repair the original device or controller far enough to let it decrypt its own data. We explain which route applies to your device before any work begins. See mobile phone recovery, Mac recovery and SSD recovery.

Devices that respond well to NAND-level recovery

• USB flash drives and memory cards of every type
• Older SATA SSDs and many budget SSDs without hardware encryption
• Dash cams, body cams, drones and action cameras
• Voice recorders, GPS units and e-readers
• Older phones and tablets with unencrypted eMMC storage
• Game consoles and handhelds with eMMC storage
• Industrial CompactFlash and embedded storage modules
• Fire, water and crush damaged devices of all kinds

Chips and controllers we work with, 2013 to 2026

The flash memory generations and controller families behind the devices we recover, by the years they were in production. The part number is laser-etched on top of the chip itself, so the device normally has to be opened to read it.

Not listed? These are examples, not limits. If your model is missing we almost certainly still recover it. Give us the number when you start a case.

A track record in NAND recovery

RMLD has an established record in NAND recoveries and continues to invest in research, development and training as chip designs change. Call (951) 595-8065 for advice, or start a case and tell us about the device.