The sudden appearance of a notification that SD card is damaged or requires formatting causes panic in any smartphone owner. You insert the drive into the slot, hoping to see your photos and documents, but the Android system persistently offers to erase all the contents in order to “correct” errors. This is a critical moment when one wrong action can lead to the irretrievable loss of important information.
Before clicking the "OK" or "Format" button, you must stop any actions with the drive. Writing new data or attempting a forced reset through the phone menu often makes file recovery impossible. In this article, we will look at why a RAW file system error occurs, how to safely extract data, and what methods exist to repair the media without losing information.
⚠️ Attention: If the card stores critical data, stop any attempts to write to it. Every second of operation of a damaged file system reduces the chances of successful recovery.
Why Android reports drive corruption
The main reason for the appearance of the “SD card is damaged” message lies in the violation of the file system structure. The Android operating system uses FAT32 or exFAT standards to read external storage devices. If the partition header or file distribution table is damaged, the phone cannot correctly determine the content and classifies the media as RAW. This does not always mean the physical death of the memory chip.
Often the problem occurs due to incorrect removal of the card. If you removed microSD while writing a file or running an application, the cache did not have time to synchronize with the physical media. Also, the cause may be power surges, overheating of the controller, or simple wear and tear of memory cells after several years of active use.
Sometimes the culprit is the smartphone card reader itself. The contacts in the slot may become oxidized or dirty, resulting in signal loss and read errors. In rare cases, the problem is caused by a software conflict after a firmware update, when drivers stop working correctly with old partitioning standards.
- 🔌 Incorrect removal of the card while the system is running.
- 💾 Logical file system errors (damage to the boot sector).
- 🔋 Power surges or unstable power supply to the slot.
- 🦠 Virus infection that hides files or changes attributes.
Primary diagnostics and safe data extraction
The most important step is to try to copy the data before any repair manipulations. If your phone allows you to open the file manager despite the error, immediately copy important files to internal memory or cloud storage. However, most often access to files is blocked and a connection to a computer is required.
Connect the smartphone to the PC via a USB cable in file transfer mode (MTP). If the computer also does not see the card or asks you to format it, use an external card reader. Connecting directly to the computer's motherboard via a USB port often gives a more stable signal than via a telephone.
To recover data, use specialized software that works with disk images. apps like Recuva, R-Studio or DMDE are able to ignore file system errors and read data sector by sector. Running a scan in the "Deep Analysis" mode allows you to find files even if the partition table is damaged.
Before launching recovery apps, create a full image of the card (.img file), if the software allows it. Work with the image, not the physical card, so as not to completely destroy it.
⚠️ Attention: Never save recovered files to the same damaged SD card. This will lead to overwriting the remaining data.
Checking and correcting errors via a computer (CHKDSK)
If the data has been saved or its value is low, you can try to restore the card to normal operation using standard Windows tools. The utility CHKDSK (Check Disk) can correct logical errors and mark bad sectors. To do this, connect the card to the PC and find out its drive letter in “My Computer”.
Run the command prompt as administrator. Enter the command, replacing X: the letter of your card. This utility attempts to fix file system errors and restore readable sectors. The process can take from several minutes to several hours, depending on the volume and degree of damage.
chkdsk X: /f /rThe parameter /f is responsible for correcting errors, and /r starts a search for damaged sectors and an attempt to restore information. If the system displays a message that the volume cannot be locked, make sure that no apps are accessing the card. If successful, Android should then correctly detect the drive.
☑️ Diagnostics via PC
| Error code | Problem description | Probability of solution |
|---|---|---|
RAW |
The file system is not recognized | High (via formatting) |
0x80070570 |
The file or directory is damaged | Medium (via CHKDSK) |
No media |
Card is not physically detected | Low (replacement required) |
Format required |
Logical partition table failure | High (without data loss possible) |
Recovery via Android terminal (ADB)
If there is no computer at hand, advanced users can try to fix errors directly on the smartphone. This will require root access and a terminal application, for example Termux or Android Terminal Emulator. This method allows you to run an analogue of the file system check utility inside the Android OS.
After obtaining superuser rights, enter the command to check and restore the file system. Please note that the device must be unmounted before testing. In modern versions of Android, the path to the block device may be different, usually it is /dev/block/mmcblk1p1 or similar.
su
fsck.vfat -aw /dev/block/mmcblk1p1
The command fsck.vfat checks the integrity of the FAT file system. The key -a means automatic correction, and -w records changes. Be extremely careful: an incorrectly specified device can damage the internal memory of the phone.
Where can I find the device name?
In Termux, enter the command 'ls /dev/block/' and look for devices named mmcblk. Usually the internal memory is mmcblk0, and the SD card is mmcblk1.
Format as a last resort
If none of the recovery methods helped, the only option left is full formatting. This action will delete all data, but may bring the card back to life for further use. It is better to format not through the phone menu, but using a computer, selecting the correct file system.
For cards up to 32 GB, it is recommended to choose FAT32, since it is most compatible with Android. For drives over 32 GB, use exFAT. Avoid the NTFS system, as many smartphones cannot write to this format without additional drivers.
In the Windows format window, uncheck the "Quick Format" box if you want the system to check the physical surface for bad sectors. This will take more time, but will identify real problems with the hardware. If the process fails, the card will most likely have to be disposed of.
⚠️ Attention: Full formatting (without the "Quick" checkbox) creates a large load on the memory controller. If the card is old, this may be the last test that it will not pass.
If formatting fails or freezes at 10-20%, this is a sure sign of physical degradation of the memory chips. It is dangerous to use such a card.
Physical damage and choosing a new card
Sometimes the problem lies not in the software, but in the physical condition of the contacts or controller. Inspect the gold contacts on the card: if they are darkened or oxidized, gently wipe them with a soft eraser or rubbing alcohol. Do not use aggressive solvents that can damage the plastic case.
If the card heats up during operation or the phone restarts when it is inserted, the controller may fail. In this case, software methods are powerless. When purchasing a new card, pay attention to the speed class (Class 10, UHS-I) and brand. Cheap no-name cards often use relabeled memory of low quality.
To record 4K video or install applications, be sure to choose cards with marking A1 or A2. These standards guarantee high random read and write speeds, which is critical for stable Android operation. Saving on storage often leads to data loss at the most inopportune moment.
- 🏷️ Buy cards only from authorized dealers (SanDisk, Samsung, Kingston).
- ⚡ Pay attention to the speed markings (V30, A2) for heavy tasks.
- 🛡️ Regularly backup important data to the cloud.
Frequently asked questions (FAQ)
Is it possible to restore a photo if I have already clicked "Format"?
There are chances, but they depend on whether Full or quick formatting. With quick formatting, the data is not physically overwritten, but is only marked as free space. Use data recovery apps immediately, before new information is written to the card.
Why does the phone see the card, but cannot save files to it?
This may indicate that the Read-Only mode is enabled due to errors, the card is full, or a physical lock (if there is a Lock switch on the SD adapter). It is also possible that the card has exhausted its resource of rewrite cycles.
Is it safe to use the card after recovery via CHKDSK?
You can use such a card, but with caution. Logical errors have been corrected, but if the cause was physical wear and tear, the failure may recur at any time. Do not store the only copy of important documents on the restored card.
How to distinguish a fake memory card from the original?
Fake cards often have a real capacity less than declared (the firmware deceives the system). Use the utility H2testw on a PC: it will record data for the entire volume and check its integrity. If write errors appear after a certain limit, the card is fake.