Technology Explained

Can Magnets Ruin An SD Card? 6 Common Reasons Why You Can’t Use Your SD Card

Joshua Lockhart 27-06-2013

sd card magnetsGuess what – magnets can’t ruin your SD cards. Let’s just get that one out in the open. Flash memory just doesn’t work that way! I mean, magnets could work, but it would have to be really, really powerful. Nothing that you have in your household would ruin one, for the record. So yeah, let’s just dispel that myth.


However, there are a variety of reasons that you can’t your SD card, and it seems as though nearly everyone faces the same issues. Below are six simple SD obstacles that most tech users face, and for a few of them, there are actual solutions. Use this article as a troubleshooting tool so you can handle your SD card woes.

It’s In The Wrong Format

sd card magnets

Let’s say that you supposedly have a blank SD card, and you’re ready to roll. However, for some reason it just isn’t working. Well, think about the last time that you used the particular card in question. Have you used it in multiple devices? Different phones? Different cameras? That may be your problem.

There’s a chance that your SD card is actually formatted for a different device. The reason it isn’t working is the very same reason that hard drives formatted for different operating systems From FAT To NTFS To ZFS: File Systems Demystified Different hard drives and operating systems may use different file systems. Here's what that means and what you need to know. Read More can’t be read by your computer. In this case, make sure you have removed any important files from the card onto your PC, and then reformat the card using your new device.

You Unsafely Ejected It

magnets and sd cards


Bad news kid – there’s a reason that you should safely remove your SD cards. Imagine throwing a wrench into the spinning gears of a fast-moving machine. One, it’s going to stop. Two, it’s probably not going to work anymore.The same principle applies to SD cards (minus the spinning gears). If you take it out of your PC while it’s still being read, you could possibly cause problems!

Most of the time, the files won’t be corrupted. However, if you do happen to screw things up, the card itself should still be usable. Chances are that you will actually have to reformat it, though (bummer). From now on, make sure you safely remove it just as a security precaution.

The Casing Is Damaged

magnets and sd cards

Sometimes it’s all about physical damage. Believe it or not, SD cards can’t handle nuclear explosions, forest fires, or tsunamis. Furthermore, they can’t handle little problems like being lost in the washing machine or crushed by a heavy object. There are recovery services for these cards, but they are very, very expensive. Sometimes they can be thousands of dollars.


Do yourself a favor by keeping loose SD cards in their proper cases, and force yourself to be organized by putting them in a safe place each and every time you are done using them. (Extra tip: another common reason people can’t use their SD cards is because they can’t find them – take it from someone who has experience.)

The Card Is Locked

magnets and sd cards

We’ve covered this on MakeUseOf before, but SD cards actually have the ability to be locked so none of the files are changed or erased – pretty nifty. While it’s a safety precaution, it’s also a nuisance for some users. However, it’s very easy to lock and unlock your card.

If you look on the side of the card, you’ll notice that there’s a little switch (it’s usually a different color from the rest of the device). Just flip it away from the locked position, and you’re golden. Yep, it really is that easy.


Your Card Reader Is Too Slow

magnet destroy sd card

I’ve faced this situation before! It was really annoying. If you have an older or cheapie card reader (whether it be external or on your PC), then it very well may not keep up with the speeds of today’s SD cards. Sometimes, if you have connected your camera to your PC with a USB cord, the transfer rate isn’t quite fast enough either.

An easy fix is to simply find a newer, faster SD card that can properly read your cards. They aren’t too expensive, and in the long run, it will definitely be worth it.

The Write Speed Isn’t Fast Enough

sd card magnets

In a similar fashion to your card reader, there’s the possibility that your SD card is too old or too slow for the device you are using it on. Use your manual to find out the write speeds of your device, and this should be an easy fix.

The only real solution to this is to purchase a new card. However, I doubt you have any attachments to your SD cards. I mean, maybe you do. In that case, tough luck.



SD cards are pretty darn handy, and you can read more about them in my article: How To Choose The Right SD Card For The Job How To Choose The Right SD Card For The Job SD cards aren't all about storage! In fact, there are several other factors to consider, and when purchasing your cards, you should make yourself aware of them. That said, SD cards aren't all created equal,... Read More .

What other reasons prevent you from using an SD card? Do you have any extra tips for other readers?

Affiliate Disclosure: By buying the products we recommend, you help keep the site alive. Read more.

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  1. Luis Arredondo
    May 21, 2018 at 8:28 pm

    I got two SDA10/32GB cards magnetized by a Microsoft Arc mouse (it has a mild magnet in the bottom side to keep attach the usb receiver when not in use).
    By mistake packed them in the same pouch I carried my mouse. Tried to format from my laptop and it didn't even read the cards, tried using a nikon d750 and a Canon 6D and neither of them were able to either read the cards or format them. I absolutely reccomend not to get SD cards any close to a magnet unless u want to try your luck.

  2. Lisa O
    July 2, 2013 at 2:06 pm

    If you use your SD cards as alternative of USB sticks like me, consider collecting all programs and files you put in the SD card in one folder, so next time you have to format the card, you can simply copy everything instead of wasting time installing everything again (in my case, portable apps and a variety of recovery/rescue discs).

  3. pmshah
    July 1, 2013 at 7:02 am

    Ever since SDHC cards have been introduced the situation has reversed for me. The side tab does nothing and I can right to the card regardless of the tab position. I have come to realise that the cameras that use SDHC cards have "write protection tab" position sensors but none of the standalone readers have this. I have a 10 year old Datafab card reader which supports cards only up to 4 GB has this protection function. I have unsuccessfully searched for over 2 years and have also had communication with SanDisk about this without success.

    I used to use such "write protected" cards with "portableapps" virus cleaning solutions. I have 4 cards which I can use with my old reader and protect them for dear life. There is no alternate solution even on the horizon.

  4. Brandon Ragoo
    June 30, 2013 at 2:27 am

    Interesting..... I often used the wonder the difference between all these SD cards.

  5. Dave Muckey
    June 30, 2013 at 12:50 am

    Conversely, you might have an older device that cannot read anything beyond a Class 1 or 2 card.

    Or maybe I should just pop for a new camera.

  6. hildyj
    June 29, 2013 at 10:00 pm

    Another reason is the letters after "SD" (like "HC"). For example, a reader that can handle SDHC can handle SD but one that's built for SD cannot use SDHC. The letters after "SD" indicate cards that support more bites (HC stands for High Capacity) or faster speeds. Make sure you buy a card that works with your equipment. Also, SD cards come in standard, mini, and micro sizes. Make sure you get the right size.

    For PCs, both issues can be cured with a external card reader that supports enhanced cards and multiple sizes. But keep in mind that cards still fail (more often, in my experience, than hard drives). Buy cards from a reputable manufacturer. If you are going to use them for backups (which I do) or long term storage, buy twice as many cards and store things redundantly.

  7. jonny rocket
    June 29, 2013 at 8:00 pm

    utter nonsense. a strong magnet will WIPE an sd card. i have done it.

    • Joshua Lockhart
      June 29, 2013 at 8:14 pm

      "I mean, magnets could work, but it would have to be really, really powerful."

  8. Pat oleary
    June 29, 2013 at 7:39 pm

    One frustrating thing about slower cards is that they may be OK for recording standard definition TV broadcasts, but will fall over, perhaps in the middle of the recording, for HD. Class 10 seems to be good for all TV data rates.

  9. Anandu B Ajith
    June 29, 2013 at 1:11 pm

    Mine Gets Write Protected.Cant Format.please Help

  10. BAM
    June 29, 2013 at 5:56 am

    The biggest problem I've been having with SD cards lately is the casing becoming brittle and disintegrating. Not a huge problem until its the write protect switch that falls out and the card is stuck permanently write protected..

  11. Stephanie Staker
    June 28, 2013 at 9:49 pm

    Thanks for the informative article, Joshua. All of this makes know, that old "common sense" that seems to have disappeared in our society? :)

  12. jumbo
    June 28, 2013 at 7:38 pm

    I have a question for you or the readers, most sd cards use fat32 format correct? And Android supports this format right? meaning I can simply switch a card between my Windows laptop and Android tablet?

    • Lisa O
      July 2, 2013 at 2:09 pm

      Yes. That works for me.

  13. Steve
    June 28, 2013 at 1:30 pm

    File system can matter. GPS navigator devices that use SD cards for map updates (due to memory space problems) may not read from an NTFS formatted card. Reformat your card, and download your update again (also, a device may only be capable of addressing a limited size of memory card, say 8 GB) . PROOF READ this article has at least 2 omitted or incorrect wordings.

  14. Steve
    June 28, 2013 at 8:39 am

    One thing I do with all of my SD cards & USB sticks is to add a simple .txt file in the root folder, which includes my name, phone No's (incl international codes) & an email address.
    If it did get lost & handed in or stolen & maybe recovered by police - there is a chance someone is savvy enough to find the text file & you might possible be reunited with your files. There are some decent people in the world.

    I remember reading many years ago about the local Post Office sorting office that trays & trays of 35mm film cases that had come out of postage envelopes & they had no way of returning them to there owners as they had no details.

    Just a thought!

  15. Harry J Wohlsein Jr.
    June 28, 2013 at 4:49 am

    Great information, one comment the last couple of sd cards I bought did not come with a case.

  16. Ari
    June 28, 2013 at 2:53 am

    I once had an SD card whose lock switch broke off and it was in the lock position...

    • Charlie O.
      June 29, 2013 at 4:44 am

      DUDE! This is like the beginning of one of the greatest stories ever told! My dad would start like this and more and more people would gather around. What happens next?

  17. John
    June 28, 2013 at 1:26 am

    Reason 7 - you constantly use a 2 dollar SD card off ebay in your 3000 dollar camera to save a few bucks?
    Reason 8 - you have a 32Gb card that you keep putting more and more stuff on without backing it up to your PC .....
    Seriously though, why can't I buy a good quality branded SD card reader. Why are they all like 5 dollars from China. I want one with a nice expensive push-push mechanism like the one on my cameras - but can't find one. Also the card reader for the PC has about 57 slots on it, costs 10 dollars and is crappy ...
    rant over

  18. Ray
    June 28, 2013 at 1:20 am

    "you should securely remove your SD cards"
    How do you 'secure' your SD card to remove it?
    Do you lock it first? Do you run a security program on it first?
    Please explain what security must be invoked on your card prior to removal.

    • Joshua Lockhart
      June 29, 2013 at 4:07 am

      Safely remove. My apologies - just wrote the wrong word.

  19. Onaje Asheber
    June 27, 2013 at 11:50 pm

    Very helpful. Thank you much...

  20. Douglas Griffin
    June 27, 2013 at 9:20 pm

    Good concise article! There are thousands of people in the world who are not aware of these simple characteristics and who needlessly throw out good cards and often good devices due to simple and fixable problems. Some even feel like they've lost hundreds of precious pictures.

    The worst case is when people who do know this information, take advantage of those who don't. They charge unreasonable fees to recover data, even though the solution is simple. I hope that many people read this in order to avoid the frustration and cost which often come from SD card troubles.

  21. Charlie O.
    June 27, 2013 at 8:31 pm

    Josh, gotta say: your article was concise, informative and useful. For the scope this subject needs, I'd say you got the tempo,length and depth just right. HOWEVER, Doc and Morris are right. MUO needs writers as much as it may be a stepping stone for future writers. You need to get your work checked by someone you trust before you publish. In this industry, you need to remember two things (OK, you need to remember LOTS and LOTS of stuff, but here's two that are relevant): 1) everything you put out there is for all mortal time; no take backs, no breaksies. 2) your reputation WILL precede you.

    Toughen up. This article is a great learning tool; more so because of the brutality of your audience. If you're working on something more complex, look back on the lessons you learned here and get it right! Now go watch an Imagine Dragons video and get back in the game!

  22. HonYin Kok
    June 27, 2013 at 7:28 pm

    The DVD that comes with my Nikon DSLR recommend formatting the SSD periodically after you transfer the photo on your PC. I do this once a while but not every transfer and never had any problem.

    Write speed not fast enough could potentially be firmware and/or drivers issue but then everything is subjective without going thru' a more through debugging process.

  23. Morris Levy
    June 27, 2013 at 6:38 pm

    You need to learn the difference between "Insecured" and "Unsecured".

  24. Doc
    June 27, 2013 at 6:34 pm

    "However, there are a variety of reasons that you can’t your SD card" Reaaaly. Can't *what* your SD card?

    "Bad news kid – there’s a reason that you should securely remove your SD cards." *Safely*, not *securely*

    "If you take it out of your PC while it’s still being read, you could possibly cause problems!" Wrong. You can safely remove *any* device while it's being read; it's removing it while it's being *written to* that causes problems!

    • Joshua Lockhart
      June 29, 2013 at 4:06 am

      Doc, we all make mistakes - it happens. I've reviewed errors in the article, and they should be fixed. I hope that I was still be able to communicate things well enough.

      Also, "really" has two l's. Not one. I understand the emphasis on the extra a's, though.

      Furthermore, the verb that you are looking for in that particular sentence is "banana."

      Trust me, it can be used as a verb: "There are a variety of reasons that you can't banana your SD card."

      • Doc
        July 6, 2013 at 2:59 pm


  25. Robert S
    June 27, 2013 at 5:22 pm

    The lock switch isn't as secure as you think. I went looking for a REASONABLY PRICED flash drive with a write protect switch. One thing I explored was using a card with a usb adapter. Turns out the write protect switch is voluntary. It just ASKS the operating system to respect its wishes. You can still write to the card with the correct tricks.

  26. Skrell
    June 27, 2013 at 5:18 pm

    Are there any pieces of software that can make using an SDcard more reliable for data storage?

  27. Daniel Escasa
    June 27, 2013 at 3:37 pm

    Is removing the card while it's reading do any harm to the card itself? I'm pretty sure that removing it while writing will corrupt the file system, but reading?

    As to being formatted for another device – I've found that it almost doesn't matter, as all the devices on which I've used SD cards seem to use a standard format. FAT32, I think?

    • Haydn Evans
      June 27, 2013 at 7:24 pm

      Some device will use NTFS as well

      • Kieran
        June 28, 2013 at 6:15 am

        NTFS should be pretty much the standard now as opposed to FAT32. You may have issues with older computers (windows XP and further back), or some linux machines. Am not sure about macs 'cos I'm not a hipster and so don't own one :-P FAT32 will be the lowest common denominator that should be readable by anything though, if you're reformatting

  28. George
    June 27, 2013 at 8:52 am

    I have a MicroSD card that appears to be locked although has no switch for that.

  29. Omstavan Samant
    June 27, 2013 at 4:07 am

    This is the reason why i had to format(and lose my collection) quite a number of times and having to download them all over again.