Quick Diagnosis
Micro SD cards can become damaged or corrupted for a variety of reasons, including physical damage, file system corruption, or logical errors. Here are some quick things to try to diagnose the issue:
- Try the micro SD card in another device – if it doesn’t work in another device, the card itself is likely damaged
- Check for physical damage – look for any signs of broken plastic or bent metal contacts
- Try reformatting the card – this may fix software corruption issues
- Try recovering data using recovery software – if data can be recovered, the card isn’t physically damaged
If the card itself seems physically fine but you can’t access the files, the file system is likely corrupted. Attempting to repair the file system or reformat the card may fix these types of issues.
Physical Damage
One cause of micro SD card issues is physical damage to the card. The small size of micro SD cards makes them easy to bend, break, or scratch. Here are some signs of physical damage:
- Broken or bent card – the plastic housing is cracked or card is visibly warped
- Broken metal contacts – the gold metal contacts are scratched or broken off
- Heat damage – card has melted spots or burn marks
- Water damage – corrosion on the metal contacts
If you suspect physical damage, the card is likely beyond repair. The tiny components inside are very fragile and not user-serviceable. Your best bet is to replace the card in this case.
Avoiding Physical Damage
To avoid physical damage to your micro SD card:
- Handle the card carefully by the edges and avoid bending
- Keep the card protected in a case when not in use
- Don’t expose the card to heat, water, or other harsh elements
- Insert and remove the card properly without force
- Store the card in a dry, room temperature location
Proper handling and storage goes a long way towards preventing physical damage. Unfortunately, the small size makes micro SD cards quite fragile. Take care when transporting and using them.
File System Errors
Another common issue with micro SD cards is file system corruption. The file system manages how data is stored on the card. If it gets corrupted, the data may be inaccessible even if the card is physically fine.
Some signs of file system corruption:
- Error messages about the card needing to be formatted
- Card reporting incorrect total memory capacity
- Failure to read/write files or folders
- Strange characters in folder/file names
- Files disappearing from the card
File system corruption can happen if the card is removed during a write operation, experiences sudden power loss, or endures other abnormal behaviour. The good news is file system errors can often be repaired.
Fixing File System Errors
Here are some steps to try and fix file system corruption:
- Copy any retrievable data off the card – use recovery software if needed
- Check the card for errors using the CHKDSK utility (Windows) or First Aid (Mac)
- Use the format function in your OS to reformat the card (will erase data!)
- Run a low-level format tool for your specific card brand
- As a last resort, initialize the card using SD Association formatting software
Formatting or low-level formatting realigns the file tables and clears out any corrupted data. Make sure to copy data off first! If the issue persists after formatting, the card may have deeper issues and require replacing.
Logical Errors
Logical errors occur when the actual data stored on the card becomes corrupted. This can happen due to:
- Improper shutdowns or removable during writes
- Faulty card readers/writers
- Exceeding the maximum read/write cycles
- Electrical issues or static discharge
- Firmware bugs or compatibility issues
- General wear and tear over time
Logical errors produce a range of symptoms:
- SD card appears empty when there should be data
- Visible files can’t be opened or are corrupted
- Data seems to disappear or change spontaneously
- Card randomly becomes read-only
- Performance slows way down
Unlike physical and file system issues, logical errors indicate fundamentally corrupted data. The card is still physically functional but the bits themselves are damaged.
Dealing With Logical Errors
There are a few steps you can try to deal with logical errors:
- Use recovery software to rescue any readable data
- Low-level format the card to overwrite corrupted sectors
- Mark bad sectors as out of use so they are avoided
- Check the card health using its built-in diagnostics tool
- Reduce write frequency to extend the card’s lifespan
Preventative measures like limiting writes and avoiding improper shutdowns will reduce the chance of logical errors occurring. But eventually, logical errors indicate an aging card nearing the end of its lifespan. Replacement is recommended for highly damaged cards exhibiting many unrecoverable sectors and reduced performance.
Using Recovery Software
Recovery software specialized for memory cards can be helpful when trying to fix a corrupted micro SD card. It works by scanning the raw data on the card and reconstructing files and file systems.
Some popular micro SD recovery software options:
- EaseUS Data Recovery Wizard – Works for SD/micro SD cards. Has free trial and paid tiers.
- Stellar Data Recovery – Claims 95% recovery rate for formatted or damaged SD cards.
- Disk Drill – Can preview recoverable files. Supports SD and micro SD cards.
- Recuva – Free SD card recovery app from the makers of CCleaner.
- TestDisk – Free and open source SD recovery software.
When using recovery software:
- Copy data off the damaged card – don’t save recovered files back to it
- Try a deep scan which reads the entire raw card data
- Beware software needing to overwrite card data to recover it
- Sort through recovered files carefully for corruption
If critical files can be successfully recovered, make backups and consider the card usable again once reformatted. But extensive data loss likely means the card should be replaced.
Preventing Corruption
You can help prevent micro SD card corruption by:
- Safely ejecting the card before removing it
- Using high-quality name brand cards from reliable manufacturers
- Avoiding extremes of heat, cold, moisture, or pressure
- Not exceeding the card’s rated write cycles or performance specs
- Regularly backing up important data stored on the card
Micro SD cards are prone to deterioration over time with normal usage. Following manufacturer guidelines for storage, environment, and formatting will maximize the card’s lifespan.
Periodically check cards that see heavy usage for errors and performance. Retiring cards that show signs of imminent failure will prevent unexpected data loss scenarios.
When to Replace a Damaged Card
If you’ve tried the recommended repair steps without success, it’s generally best to replace a damaged micro SD card in the following situations:
- Visible physical damage – broken plastic, bent card, scratched metal
- Card fails to work at all in multiple devices
- Cannot initialize, format, or partition the card anymore
- Significant unrecoverable data loss or corruption
- Card has exceeded its write cycle limit
- Erratic performance, very slow read/write speeds
A new micro SD card only costs a few dollars for smaller storage capacities. Replacement is worthwhile if you’ve exhausted repair options or the card seems to be on the verge of failure.
Select a brand, storage size, and speed class appropriate to how you intend to use the replacement card. Transfer any remaining data from the old card and properly dispose of it.
Professional Data Recovery
For extremely valuable or irreplaceable data on a failed micro SD card, professional data recovery services may be able to help where DIY options have failed. They use specialized tools and techniques in a controlled clean room environment.
Some things to note when considering professional recovery:
- It is very expensive, often over $1000 depending on the data size
- There is no guarantee all data can be recovered
- The process takes days or weeks to complete
- Physical damage often makes recovery impossible
Professional recovery makes sense for large amounts of critical business data or personal files that can’t be replaced. But for most typical consumer scenarios, purchasing a new card is the more cost effective approach.
Summary
Here are some key tips to remember when dealing with a damaged micro SD card:
- Try the card in a different device to isolate the issue
- Check for physical damage and attempt data recovery if needed
- Reformat cards with file system errors using built-in utilities
- Low-level format cards showing logical errors
- Replace extensively damaged cards rather than waste time on repairs
- Observe proper handling, storage, and usage practices to avoid issues
- Consider professional recovery for irreplaceable data as a last resort
With a careful diagnosis, the right tools, and a steady hand, you stand a good chance of reviving corrupted media. But if all else fails, remember micro SD cards themselves are inexpensive to replace.
