Several M.2 SSDs.
The controller is the brain of your solid-state drive (SSD). It is responsible for critical tasks like translating data locations, managing wear on the memory cells, correcting errors, and performing garbage collection.
When an SSD controller fails, you can’t simply run a software utility to get your files back. In this article, we’ll explain how SSD controllers operate and how data recovery engineers reconstruct files when SSD controllers fail.
If you’ve lost data due to a failed SSD, we’re here to help. Call 1-800-237-4200 to speak with a data recovery expert or submit a case online.
The SSD Controller: Key Features and Capabilities
An SSD is a sophisticated embedded system, and sophisticated systems require some engineering. The SSD controller directs every single piece of data written to or read from the NAND flash memory chips (where your files are stored).
The controller is responsible for several critical background tasks that are essential for the drive’s performance and longevity:
- Flash Translation Layer (FTL): The FTL (which does not stand for Faster Than Light, by the way) is a sort of digital map. It translates the simple block-based view of your operating system (e.g., “file X is located at sector 500”) into the complex physical locations on the NAND memory chips.
- Wear Leveling: NAND flash memory cells can only be written to a finite number of times. The controller uses wear leveling algorithms to spread write operations evenly across all the memory cells, preventing any single block from wearing out prematurely.
- Garbage Collection: To write new data to a block on an SSD, the block must first be empty. Garbage collection is a background process where the controller consolidates valid data from partially filled blocks and erases the now-empty blocks.
- Error Correction Code (ECC): As flash memory wears down, bit errors can occur. The controller constantly runs ECC algorithms to detect and correct these errors on the fly.
- Encryption: On many modern SSDs, the controller also manages automatic hardware-based encryption.
Common Causes of SSD Controller Failure
When a controller fails, the drive typically becomes completely inaccessible. Your computer may not recognize it at all, or it might show up with an incorrect size (like 0 MB) or a generic factory name. The failure can be traced back to a few primary causes:
- Firmware Corruption: The controller runs its own internal software, called firmware. A sudden power outage or other incident during a write operation can corrupt this firmware, leaving the SSD without the instructions it needs to operate.
- Physical Damage: An electrical surge or short circuit can physically destroy the controller chip or other sensitive electronic components on the circuit board. Overheating can also lead to premature failure.
- Component Wear: The controller itself is a complex chip that can simply wear out over time, though this is less common than firmware corruption or damage to the NAND cells.
- Manufacturing Defects: In some cases, a flaw in the manufacturing process can lead to a controller that fails well before its expected lifespan.
Recently, we’ve even seen SSD controller failures caused by operating system security updates — allegedly. With that said, SSD controllers are generally quite stable; during a data recovery evaluation, the engineer’s first task is to figure out exactly how and why the controller stopped operating predictably.
Why Controller Failure Makes Recovery So Complex
Contrary to popular belief, data recovery laboratories don’t resort to “chip-off” recovery as a first resort for SSD cases. You can’t just plug the memory chips into a reader and copy your data off — you need the exact SSD controller, if possible. If the controller is unrepairable, engineers must simulate that controller’s functions.
That can create novel challenges for engineers:
- Proprietary Algorithms: Every controller manufacturer (for example Phison, Silicon Motion, or Marvell) uses their own algorithms for wear leveling, data placement, and garbage collection. These complex patterns are trade secrets, so data recovery engineers must reverse engineer them to some degree.
- Data Scrambling (XOR): To improve performance and endurance, controllers intentionally spread data across multiple NAND chips using a mathematical pattern, often an XOR cipher. To reconstruct the data, you need to know the pattern.
- On-the-Fly Encryption: If the controller was managing hardware encryption, the encryption key is often stored within the controller itself. If the controller chip is physically dead, that key is lost. Successful recovery depends on complex techniques to bypass or reconstruct the encryption layer.
The Professional Recovery Process for a Failed Controller
An SSD’s internal NAND chips and controller.
To recover data from an SSD with a failed controller, engineers must have extensive working knowledge of the controller in question — and advanced tools that can recreate, repair, or simulate that controller.
This is one of the reasons that every Datarecovery.com location is equipped with a full-service laboratory: If we operated a single lab, we’d need to send every SSD case to that laboratory to get results (and unfortunately, that’s how many national data recovery chains operate).
Here’s an overview of our process:
- Advanced Diagnosis: First, we connect the drive to a specialized hardware tool that can communicate with the SSD in a low-level “factory mode.” This allows us to bypass the standard interface and interact directly with the controller and firmware. This helps us determine if the controller is physically dead or if its firmware is corrupted.
- Firmware Repair (If Possible): If the diagnosis reveals firmware corruption, our engineers use proprietary tools to reload or patch the controller’s firmware. The goal is to temporarily revive the controller just long enough to stabilize the drive and clone the user’s data.
- Chip-Off Recovery: If the controller is physically destroyed (e.g., by a power surge), the only option is a chip-off recovery. This involves carefully desoldering each NAND flash memory chip from the SSD’s circuit board and using specialized readers to create a raw image of the data stored on each chip.
From this point, data recovery might involve using proprietary software to analyze the raw data and reverse-engineer the controller’s algorithms — rebuilding the FTL map, figuring out the XOR scrambling pattern, and so on.
However, the exact process varies with the failure scenario. We provide risk-free evaluations to provide clients with a comprehensive quote and failure analysis before beginning any SSD data recovery work.
SSD Data Recovery Prognosis: In Most Cases, Failed Controllers Are Recoverable
A failed SSD controller rarely destroys the raw data on the NAND memory chips. Instead, it destroys the organization of the data — and while that complicates data recovery, our engineers are up for the challenge.
At Datarecovery.com, our engineers have spent decades developing the purpose-built systems and proprietary software required to reverse-engineer even the most complex SSD controllers. Our investments in research and development allows us to successfully recover data from severely damaged devices, including fire-damaged HDDs and SSDs. We support each case with a “no data, no charge” guarantee: If we can’t recover the data you need, you don’t pay for the attempt.
If you suspect your SSD has a failed controller, the most important step is to stop using the drive immediately to prevent further damage. Contact Datarecovery.com at 1-800-237-4200 or submit a case online for a free evaluation from our experts.
