My SD card was working fine, then suddenly stopped being recognized by my phone and computer. I have important photos and files on it, and now it shows errors or asks to be formatted. I need help figuring out if the card is corrupted, how to recover the data, and whether there’s a safe way to fix the SD card without losing everything.
I hate this problem. You finish a long shoot, or you move files after a trip, then the SD card throws errors and your stomach drops. I did this to myself more than once by yanking the card too fast. Still, the first move is not panic. A lot of the time your files are still on the card, and the part that broke is the file system, meaning the index your computer uses to find stuff.
First thing, stop writing anything to the card. Don’t put it back in your camera. Don’t record one more clip. Don’t keep reconnecting it hoping it suddenly behaves. Each write raises the odds of overwriting the files you want back.
The order matters. Recover first. Repair later. I learned this the hard way. People rush into Windows fixes, format prompts, random commands from old forum posts. Some of those tools rewrite parts of the card. Once that happens, recovery gets uglier fast.
If the files matter, I’d start with recovery software before touching repair tools. I’ve had solid results with Disk Drill. What helped me most was the byte-to-byte backup option.
Reason being, a corrupted card is sometimes more than 'corrupted.' It’s dying. A full scan keeps reading the card over and over, and a weak card can drop out mid-job. Disk Drill lets you make a full image of the card, sector by sector. Save that image to your computer, unplug the SD card, then work from the image file instead. I trust that route more. If the card quits halfway through later, your image is still there.
After your files are safe, or after you decide the data is gone and you’re moving on, then start trying to fix the card itself. This is the order I use.
1. Check the boring stuff first
Yeah, this part feels dumb. Do it anyway. I’ve seen bad readers fake a dead card more times than bad cards fake a bad reader. Try another USB port. Try a different card reader. Those tiny adapters bundled with microSD cards fail all the time. If your laptop has a built-in slot, test with a separate USB reader too. Sometimes the issue is the connection, not the storage.
2. Open Disk Management and see what Windows sees
If Windows detects the card but File Explorer does not show it, check Disk Management. Right-click Start, open Disk Management, and look for the SD card in the list. If the card is there but missing a drive letter, right-click it, pick Change Drive Letter and Paths, and assign one. I’ve had cards reappear right after doing this.
3. Run the built-in repair tool
This is the low-risk Windows option I try after recovery. In File Explorer, right-click the SD card, open Properties, go to the Tools tab, then click Check. It looks for file system errors and patches what it finds. Not magic, but it sometimes fixes cards with minor damage.
4. Use CHKDSK if the simple tool does nothing
Open Command Prompt or Terminal as Administrator. Then run chkdsk X: /r, replacing X with your SD card’s letter. The /r switch tells Windows to scan for bad sectors and recover readable data where possible. On a big card, this drags. Leave it alone and let it finish.
5. Try TestDisk when the partition looks missing
If the card shows as unallocated, or the partition vanished, TestDisk is worth a look. It’s open source and ugly in the old-school utility way, but it has saved cards people thought were empty. This is more for folks comfortable reading menus and not guessing their way through prompts.
6. Format the card if repair fails
If nothing brings it back, format it and reset the file system. If a normal format fails, a low-level format tool is the next step. I usually pick exFAT for SD cards because it works across most devices and handles large video files without drama.
If a card corrupts once, I stop trusting it. Maybe it was a fluke. Maybe not. SD cards wear out, and the limit is tied to write cycles. When one starts acting weird, I retire it from anything important. I’ll use it for throwaway transfers at most, or I toss it. Buying a fresh card from a known brand hurts less than losing a shoot.
And yeah, use Eject or Safely Remove. I ignored that advice for years. Then I paid for it. More than once tbh.
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If the card asks for format, do not format it first. I agree with @mikeappsreviewer on recovery before repair, but I would skip CHKDSK until after you pull data. CHKDSK has a habbit of “fixing” the file system in ways you do not want when photos matter.
What I’d do:
- Test the write-lock switch on the SD adapter. Half the time it slips.
- Check Device Manager. If it shows with error code 43 or keeps reconnecting, the card or reader is failing.
- On Linux or a Mac, see if the card mounts read-only. Sometimes Windows gives up sooner.
- If the card size shows wrong, like 31 MB instead of 128 GB, thers a controller failure. Stop there.
- Recover from an image, not the card itself. Disk Drill is good for this, esp if the card drops offline mid-scan.
If your phone encrypted the SD card as internal storage, normal recovery gets messy. In that case, use the same phone first.
Also, this helps:
step by step corrupted SD card data recovery video guide
After recovery, run the official SD Memory Card Formatter, not random formatter tools. If errors return after one full rewrite test, toss the card. It’s done.
If both your phone and computer suddenly stopped seeing it, I’d spend 2 minutes ruling out power/contact issues before doing any software stuff. Clean the gold contacts gently with isopropyl alcohol, let it dry, then try a powered USB card reader. A weak reader can make a borderline SD card look totally dead. That part gets missed a lot.
I agree with @mikeappsreviewer and @viajeroceleste on recover first, but I’m a little less sold on throwing every repair command at it right away. If the card is intermittently disconnecting, each retry can make things worse.
A couple extra tells:
- If the card gets hot fast, bad sign.
- If it appears/disappears in Disk Management every few seconds, also bad.
- If another identical phone/camera reads it, copy everything off there first. Sometimes the original device still has better luck.
For recovery, I’d still use Disk Drill, mainly because imaging the SD card first is the safest move when the filesystem is toast but the memory is still readable.
Also, if you want extra reading, this is actually useful:
practical corrupted microSD card recovery tips
If the card is not detected anywhere at all, not even by disk tools, that’s usually not “corruption” anymore. That’s hardware failure, and DIY options get real thin real fast. Sad but true tbh.
I’d add one thing the others only touched lightly: check whether the card is showing up with the correct capacity and partition type in a proper partition tool, not just File Explorer. If it shows as RAW, no media, or some nonsense size, don’t keep retrying mounts. That often means translation-layer or controller trouble, not a simple filesystem glitch.
Where I slightly disagree with @mikeappsreviewer is low-level formatting advice. True low-level format is not really a consumer SD card thing, and random “LLF” tools can be sketchy. If you get to the repair stage, stick to the official SD formatter or a normal full format only after data recovery is done.
My order would be:
- Test in a different reader and, if microSD, a different adapter
- Check actual size/status in Disk Management or a partition utility
- If readable at all, make an image first
- Recover files from the image, not the card
- Only then test reformat/reuse
About Disk Drill since it came up:
Pros
- easy imaging first, which is the safest move
- good preview for photos/videos
- simpler than TestDisk for most people
Cons
- not magic if the card is electrically failing
- deep scans can take a while
- free recovery limits depend on platform/version
Also worth noting: if this SD card was used in an Android phone as adoptable/internal storage, recovery on a PC may give you useless encrypted data. In that case, put it back in the same phone first and see if the phone can still access anything.
So yeah, I’m with @viajeroceleste and @sterrenkijker on avoiding random fixes too early. If the card is invisible everywhere, that’s usually hardware death, not corruption.