MicroSD Card Data Recovery
MicroSD cards are monolithic: controller and NAND memory sealed in one package. When the controller fails or the contacts break, no card reader will detect it. We bypass the controller by wiring directly into the NAND test points and reading the raw flash memory using PC-3000 Flash.
MicroSD data recovery uses a technique called chip-off: the technician sands away the card's protective epoxy, exposes copper test points on the monolithic die, solders fine wires to a spider board adapter, and reads the raw NAND flash through PC-3000 Flash or Visual NAND Reconstructor. The raw dump then goes through bad column removal, XOR decoding, ECC correction, and page reassembly to reconstruct a usable file system. Pricing at Rossmann Repair Group runs $400 to $1,800 depending on complexity, with no charge if the data is unrecoverable.
Why MicroSD Cards Need Chip-Off Recovery
MicroSD cards are built as monolithic flash storage. The controller and NAND memory are sealed together in one tiny inseparable package. There is no separate memory chip to transplant or read externally. While older, lower-capacity full-size SD cards used removable NAND chips, most modern high-capacity SD cards are also monolithic.
When the card is damaged or its controller fails, standard card readers cannot communicate with it. The only path to the data is tapping directly into the NAND flash memory interface inside the package.
Older full-size SD cards use PCB-based designs with separate NAND and controller chips, allowing standard chip-off desoldering. Modern high-capacity full-size SD cards are typically monolithic, requiring the same intensive extraction process as microSD. See our SD card data recovery page for those cases.
Why most shops decline monolithic recoveries
Monolithic recovery requires scraping away protective epoxy, locating microscopic pinouts, soldering hair-thin wires, and using flash readers that cost $10,000+ (PC-3000 Flash, Visual NAND Reconstructor). Most data recovery labs lack either the equipment or the pinout databases for these devices.
Exposed internal copper traces of a monolithic microSD card, ready for direct NAND access wiring.
Chip-Off Recovery Process
- 1
Physical Inspection
Every recovery starts under a microscope. We inspect the card's contact pads for scratches, corrosion, or cracks in the plastic shell. We check whether the controller is responding or if the internal trace connections are severed.
This inspection determines whether a simple contact repair might work or if full chip-off extraction is required.
MicroSD card inspection under microscope before recovery.
- 2
NAND Interface Exposure
We sand away the protective epoxy coating on the card's underside to reveal the copper test points that connect to the NAND die. This uses fine sandpaper starting at 1000 grit and progressing to 2500 grit to avoid gouging the traces.
One chance only
One slip gouges a trace and renders the data unrecoverable. This decapsulation step can take hours on its own.
- 3
Raw NAND Extraction
With the test points exposed, we solder fine wires to each pad and connect them to a spider board adapter on PC-3000 Flash or Visual NAND Reconstructor. These tools send low-level commands directly to the NAND die, bypassing the card's controller entirely.
The result is a raw memory dump: every page of NAND data, including spare area bytes, read sequentially. A 128 GB card produces a dump that takes hours to complete with multiple verification passes.
Spider-web wiring from monolithic microSD to PC-3000 Flash adapter: each wire maps to a NAND signal line.
- 4
Data Reconstruction
The raw dump is not usable as-is. The controller scrambled the data using proprietary algorithms. We apply four transformations to reconstruct the original file system:
Bad Column Removal
Digitally realign the raw extracted data to account for defective physical NAND columns that were mapped out and bypassed by the controller during manufacturing. Each controller family uses a different column map.
XOR Decoding
Apply the correct XOR key to unscramble the data. Our database covers patterns for Phison, Silicon Motion, SanDisk, and Samsung controllers.
ECC Correction
Simulate the controller's error correction engine to fix bit errors in each NAND page. This step determines final file integrity.
Page Reassembly
Reorder pages and blocks into their original logical sequence, rebuilding the FAT/exFAT file system the card originally used.
After reconstruction, we verify recovered files by opening a sample of photos and videos to confirm they render correctly. The recovered data is delivered on a new storage device.
Technical Terms in MicroSD Recovery
- Monolithic
- A chip design where the controller and NAND memory are separate silicon dies, wire-bonded together and encapsulated under a single protective coating. All microSD cards use monolithic construction. Unlike PCB-based devices, the components cannot be separated for individual testing or chip-off reading.
- Chip-Off
- A recovery technique that reads NAND flash memory by connecting directly to the silicon die. For monolithic devices, this means exposing internal test points rather than physically removing a chip from a PCB.
- XOR Decoding
- Flash controllers scramble stored data using bitwise XOR operations with a key specific to the controller model. Raw NAND dumps are unreadable until the correct XOR key is applied to reverse the scrambling.
- ECC (Error Correction Code)
- Algorithms (typically BCH or LDPC) used by flash controllers to detect and correct bit errors in NAND pages. During recovery, the technician must replicate the controller's ECC engine to fix errors introduced by NAND wear or read instability.
- Bad Column Removal
- NAND flash dies have defective columns identified and mapped out during manufacturing. The controller bypasses these locations entirely during normal operation. During chip-off reconstruction, the raw dump appears misaligned because the extraction tool reads straight across the die. The recovery software must digitally shift the page layout to account for the bypassed columns.
- Spider Board
- A precision hardware adapter designed to interface with NAND signal lines on a monolithic chip. A precision hardware adapter designed to interface with NAND signal lines on a monolithic chip using microscopic needle probes, eliminating the need for soldering wires directly to the fragile test points. The adapter routes these signals to PC-3000 Flash or Visual NAND Reconstructor for data extraction.
Types of MicroSD Failures We Recover
Physical Damage
Severed contact pad traces prevent the card from being detected. We wire directly into the internal test points, bypassing the damaged contacts.
Cards bent, cracked, or snapped in half are recoverable as long as the silicon die is not fractured. We have recovered data from cards broken into two pieces.
NAND flash cells tolerate brief water exposure. We clean the card, resolve shorted components, and perform chip-off extraction if the controller is damaged.
Controller and Logical Failures
Card not detected or showing 0 bytes. The NAND cells are intact but inaccessible through normal interfaces. Chip-off recovery bypasses the failed controller.
The card mounts but freezes, requests formatting, or shows the wrong capacity. Chip-off extraction bypasses the firmware layer entirely.
Heavily used cards develop uncorrectable bit errors. We extract the raw dump and apply ECC correction. Severe degradation limits recovery, but partial recovery is often possible.
For cards that still mount but show missing or corrupted files, we create a forensic image, reconstruct the flash translation layer mapping, and recover files from the rebuilt filesystem. If the filesystem metadata is too damaged, we fall back to file carving using known binary signatures.
Case Study: 128 GB SanDisk MicroSD with Scratched Contacts
A customer sent a 128 GB SanDisk microSD card from a GoPro that stopped being detected. The full recovery is documented in the video embedded here.
Diagnosis
Deep scratches on the gold contact pads had severed several copper traces connecting the card's external interface to the internal NAND. The controller could not communicate with any reader.
Recovery
Sanded down the epoxy coating, identified the pinout, soldered 20+ wires to a spider board, and extracted the raw NAND dump. The controller was a Phison variant requiring XOR decoding before file system reconstruction.
Outcome
Recovered all 1,200+ photos and 20 GB of 4K video. Every video file rendered correctly. Total bench time: approximately 2 days.
Monolithic Flash Challenges
No Standard Pinout
Every monolithic card model has different test point locations and signal assignments. We maintain an internal pinout library and can map new pinouts when a card model is not in our database.
Controller Algorithm Variety
Phison, Silicon Motion, SanDisk, and Samsung each use proprietary XOR keys, ECC implementations, and page ordering schemes. Identifying the correct controller family is the first step in choosing the right reconstruction algorithm.
NAND Density and Error Rates
SLC, MLC, TLC, and 3D TLC NAND have progressively higher bit error rates. Higher-density cards require stronger ECC and more reconstruction passes. TLC cards with heavy wear may have partial recovery limitations.
Pricing
| Service Tier | Price Range | Description |
|---|---|---|
| Standard MicroSD Recovery | $400 - $900 | Controller failure or minor physical damage. Card not detected but no severe trauma to the die. |
| Complex Monolithic Chip-Off | $900 - $1,800 | Severe physical damage, unknown pinout requiring mapping, heavy NAND wear requiring extended ECC work. |
No Data, No Fee
If we cannot recover your data, you pay nothing. See our no-fix-no-fee policy.
Turnaround
Standard: 3-7 business days. Complex monolithic cases may take longer. Rush service available.
Unrecoverable Cases
If NAND cells are physically destroyed or degraded beyond what ECC can correct, we tell you promptly and do not charge.
Data Recovery Standards & Verification
Our Austin lab operates on a transparency-first model. We use industry-standard recovery tools, including PC-3000 and DeepSpar, combined with strict environmental controls to make sure your hard drive is handled safely and properly. This approach allows us to serve clients nationwide with consistent technical standards.
Open-drive work is performed in a ULPA-filtered laminar-flow bench, validated to 0.02 µm particle count, verified using TSI P-Trak instrumentation.
Transparent History
Serving clients nationwide via mail-in service since 2008.
Media Coverage
Our repair work has been covered by The Wall Street Journal and Business Insider, with CBC News reporting on our pricing transparency. Louis Rossmann has testified in Right to Repair hearings in multiple states and founded the Repair Preservation Group.
Aligned Incentives
Our "No Data, No Charge" policy means we assume the risk of the recovery attempt, not the client.
Technical Oversight
Louis Rossmann
Louis Rossmann's well trained staff review our lab protocols to ensure technical accuracy and honest service. Since 2008, his focus has been on clear technical communication and accurate diagnostics rather than sales-driven explanations.
We believe in proving standards rather than just stating them. We use TSI P-Trak instrumentation to verify that clean-air benchmarks are met before any drive is opened.
See our clean bench validation data and particle test videoBefore You Ship Your Card
Do NOT:
- Try to open, sand, or repair the card yourself; one mistake destroys the data permanently
- Run data recovery software on a physically damaged card
- Keep inserting it into different readers or devices
- Apply heat, freeze the card, or clean contacts with abrasives
Do:
- Place the card in a rigid container (pill case, SD holder)
- Store in a cool, dry location away from magnets
- Include a note describing how the failure occurred
- Follow our shipping instructions for safe transit
Frequently Asked Questions
Can you recover data from a physically broken microSD card?
What is the difference between SD card recovery and microSD recovery?
Why is monolithic flash recovery more expensive than standard drive recovery?
Can you recover data from a microSD card that is not detected?
How long does microSD data recovery take?
What does chip-off recovery mean for microSD cards?
Is data still on a dead microSD card?
How should I ship a microSD card for recovery?
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Complete service catalog
Send us your microSD card
Free evaluation. No data, no charge. Mail-in from anywhere in the U.S.