SD cards are widely used in Android phones and other devices for expanding storage capacity. However, sometimes these cards can suddenly stop working, leading to data loss and frustration. This is a common issue that can happen for various reasons.
When an SD card fails in Android, you will typically get an error message saying the card is corrupted or damaged. The phone may fail to detect the card entirely or show it as unmounted external storage. This renders all data on the card inaccessible.
There are several potential causes of SD card failure on Android devices. These include file system corruption, improper ejection of the card, physical damage, outdated drivers, malware infection, exceeding the card’s lifespan, fake/counterfeit cards, and incorrect storage format.
Losing access to data stored on an SD card can be a major inconvenience. Photos, videos, music, app data and other files will suddenly become unavailable. Important files may be lost forever if no backup exists. Understanding what causes SD card failure can help you avoid it and be prepared with preventative measures.
Corrupted File System
File system corruption happens when the file system structure on the SD card becomes damaged. This can occur due to improper ejection, malware, or exceeding the card’s lifespan. The file system manages how data is stored and retrieved on the card, so corruption prevents the operating system from properly accessing files.
On SD cards, the most common file systems are FAT32 and exFAT. These allocate storage space into clusters and use metadata like the file allocation table to track what clusters belong to each file. If this metadata becomes corrupted, the locations of file data can be lost. The operating system will be unable to fully read or write files if it cannot follow the file system’s structure.
Symptoms of file system corruption include getting I/O errors when trying to access files, inability to modify or delete files, missing or truncated files, and the operating system asking to format the card before use. Corrupted cards may also show a different capacity than advertised. While the physical storage space remains intact, damage to file system structures renders some of it inaccessible.[1]
Improper Ejection
One of the most common reasons an SD card may suddenly stop working on Android is if it was improperly ejected. Android requires SD cards to be “ejected” before removing them to prevent file corruption. If the card is abruptly disconnected without ejecting, the file system can become corrupted and unreadable by Android.
As one Reddit user explained after accidentally ejecting their SD card, “This just means you unmounted the card (or other external storage) in the system. Remove the card (or device e.g. USB) and reinstall.” [1] While the data may still be intact, Android can no longer communicate properly with the SD card after improper removal.
To safely remove an SD card on Android, users should navigate to Storage Settings, tap the SD card name, and select “Eject.” This ensures any open files are closed and caches are flushed before disconnecting. Once ejected, the card can be removed without risk of corruption. Attempting to remove the card without ejecting can lead to lost files, photography corruption, or render the card completely unusable until reformatted.
Physical Damage
One of the most common causes of SD card failure is physical damage from dropping, bending, or otherwise mistreating the card. SD cards have delicate internal components that can break if exposed to physical shocks or stress. For example, dropping an SD card even a few feet onto a hard surface can damage the card’s circuit board or internal memory chips. Likewise, sitting on a card, bending it, or jamming it forcefully into a device can break internal parts. SD cards are not indestructible and need to be handled with care.
Signs that an SD card has been physically damaged include the card not being recognized by the device, corrupted data, the device freezing when the card is inserted, or error messages about the card being unreadable. If an SD card has any visible signs of damage like cracks, dents, or bends, that is a clear indication of physical damage. In some cases, even a card that looks fine externally may have suffered internal damage that renders it unusable.
When physical damage occurs, data recovery from the SD card gets extremely difficult. However, companies like DriveSavers offer advanced recovery services designed to rescue data from damaged media. This involves disassembling the SD card in a dust-free cleanroom and working at the component level to repair and reconstruct the files stored on the internal memory chips. While pricey, data recovery is sometimes the only option after physical damage if the files on the card were irreplaceable.
Outdated Drivers
One common reason an SD card may stop working on Android is outdated device drivers. Device drivers act as the software interface between the operating system and hardware components like the SD card reader. Over time, updates to Android and hardware can render old drivers incompatible, leading to SD card failures.
Symptoms of outdated SD card drivers include the phone not detecting the card at all, inability to access files, or general read/write errors. To confirm it’s a driver issue, try the SD card on another device – if it works fine, outdated drivers on your Android are likely the culprit.
Updating the drivers is an easy fix in most cases. On Android, drivers for core components like the SD card are bundled with system updates. Checking for and installing any available operating system updates through Settings is the first step. For Samsung devices, the Samsung Smart Switch app can also update drivers. As a last resort, a factory reset may update all drivers, but backup data first. Keeping Android and drivers updated will prevent most issues from outdated software.
Malware Infection
Android malware can sometimes target storage devices like SD cards, infecting them with malicious files. According to Securelist, malware was responsible for 67.78% of mobile attacks in 2022. When an SD card becomes infected, any device it is inserted into is at risk of infection [1]. Signs of an infected SD card include strange popups, app crashes, and reduced performance. To prevent infection, only install apps from trusted sources like the Play Store, avoid “sideloading” untrusted APKs, install mobile anti-virus software, and don’t insert your SD card into untrusted devices [2].
Exceeding Lifespan
SD cards have a limited lifespan and can only withstand a certain number of write cycles before failing. The lifespan depends on the quality and type of NAND flash memory used. Lower-end cards may last 1-3 years with heavy usage, while high-end cards can last 5-10 years.
One way to monitor lifespan is to use tools like H2testw which checks for bad blocks and errors. As the card ages, the number of bad blocks will increase indicating it’s nearing end of life. Another option is SD Card Monitor which tracks used capacity and wear level.
It’s generally recommended to retire SD cards used in security cameras and other write-intensive applications after 2-3 years. For light usage in phones or laptops, plan to replace cards every 4-5 years. Backing up data periodically allows safely retiring cards once performance declines.
Some signs it’s time to replace an aging SD card: frequent corruption or data loss, dramatically slower performance, increasing bad blocks or errors. Proactively replacing cards before failure prevents lost photos, videos, and other data.
Sources:
https://superuser.com/questions/17350/whats-the-life-expectancy-of-an-sd-card
https://www.reddit.com/r/DataHoarder/comments/qla6on/lifespan_of_micro_sd_card/
Using a Fake Card
Many counterfeit and low quality SD cards have flooded the market in recent years. These fake cards often initially seem to work fine, but end up corrupting or losing data over time. According to one Reddit user’s experience, files can initially be written to fake cards successfully but eventually get overwritten as the card reaches its real capacity.
There are a few signs that can indicate an SD card is counterfeit:
- It has a name you don’t recognize
- It claims to have an unusually high capacity for a low price
- The packaging contains spelling/grammar errors
- Performance is very slow despite high claimed speeds
The safest way to avoid fake cards is to only buy from reputable major brands like SanDisk, Samsung, or Kingston. Purchasing from well-known retailers is also recommended over random sellers online or at flea markets. The small upfront savings from a sketchy source doesn’t outweigh losing irreplaceable data down the road.
Incorrect Storage Format
Android is designed to work with specific file systems for external storage like SD cards. The most common compatible file systems are FAT32, exFAT, and ext4 1. If the SD card is formatted with an incompatible file system like NTFS or HFS+, Android will not be able to properly read from or write to the card.
When inserted into an Android device, an incompatible SD card may prompt an error to format the card. Formatting will erase all data, so first try to backup any important files. Then use a computer to reformat the SD card to FAT32 or exFAT which are widely compatible. Avoid NTFS which is designed for Windows PCs.
Some Android devices may be able to read certain file systems like NTFS but have broken or unreliable write support, leading to unexpected errors. So sticking with the standard FAT32 or exFAT formats will provide the most stable performance.
If formatting the card does not resolve read/write issues, the card itself may be damaged or counterfeit. Trying a different high-quality card that follows SD standard specifications can often fix formatting problems.
Preventing Failures
There are several steps you can take to prevent SD card failures from happening in the first place:
Back up your data regularly. Copy your photos, videos, and other files off the SD card to your computer or cloud storage. That way, if the card does fail, you won’t lose anything important. Make backing up a habit so you always have a redundant copy of your data.
Handle SD cards properly. Avoid exposing them to moisture, extreme heat, bending, and physical impacts which can damage the card. When removing the card from your device or card reader, use the “Eject” function first rather than pulling it out abruptly while still in use (Source).
Buy quality SD cards from reputable brands like SanDisk or Samsung. Lower-quality or fake cards are more prone to failures and corruption. Stick to well-known brands and check reviews to ensure you’re getting a genuine, high-endurance product (Source).
Monitor the health of your SD card with tools like SD Card Monitor which can warn you if performance is declining. Replace cards proactively once they near the end of their rated lifespan.
Following best practices for handling, buying, and maintaining your SD cards will significantly reduce the chances of them failing unexpectedly.