Question about Canon PowerShot SD550 / IXUS 750 Digital Camera

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Unlock card OK, so I am a tech idiot. I just bought a new Canon S3 IS camera and am trying for the first time to insert a memory card (Sandisk Pro Duo 2MG). I think I have it inserted, but the camera reads "memory card locked". How do I unlock the memory card?

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  • garybr Aug 26, 2007

    I see a very small notch on the side, but it does not appear to have a slider on it.

  • garybr Aug 26, 2007

    Here is a picture of the card that I have.

  • garybr Aug 26, 2007

    Except mine is a 2GB.

  • garybr Aug 26, 2007

    Thanks for the link, but my camera is the Canon Powershot S3 IS. It looks like it is compatible.

  • garybr Aug 26, 2007

    Looks like I was reading that wrong. It does appear that they are not compatible now. I don't have another card to use, but I will head back to Circuit City today. I feel like I spent a lot of money and got the card that THEY recommended. It would figure that it is not the right card. :-(

  • garybr Aug 26, 2007

    Thanks, I will let you know.

    I did try my phone memory card (forgot I had that) in it, since I am going to have to wait until the store opens.

    This memory card is a Motorola Micro SD. With the adapter, it fits the camera slot perfectly. However, the screen on the camera still reads "memory card locked". This card has a slide on the side, which is on "unlocked". Do you know a site that I can check the compatibility of that?



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Take the card out from the camera & you should see a small slider on the side. Set the slider "up" as per the attached picture. Please update the question & let us know if the information given was useful to you - Good Luck!

Posted on Aug 26, 2007

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  • Greg Cann
    Greg Cann Aug 26, 2007

    This card does not appear to have the switch so should work if compatible with your camera.

    You can try lightly cleaning the contacts of the card with a pencil eraser or soft cloth.
    Perhaps try the card in a PC card reader to make sure it's OK. Also try & find someone with another SD card you can try in your camera.

    I looked at the Sandisk website & they don't list that card as being compatible with your camera although that doesn't necessarily mean that it isn't!!

    See the link below:

    Best regards,

  • Greg Cann
    Greg Cann Aug 26, 2007

    Sorry I only see SD cards in the compatibilty list for the S3 IS not the SanDisk Extreme® III MS PRO Duo 2GB?

    See if you can find another card to try.

    Best regards,

  • Greg Cann
    Greg Cann Aug 26, 2007

    Let us know how you get on & which card you get.

    Best regards,

  • Greg Cann
    Greg Cann Aug 26, 2007

    The cards are notoriously unreliable as the tiny mechanical slider can get worn & the camera not register it correctly.
    The usual practice is to put a small piece of tape over the whole switch position as indicated in the picture, I suggest you try that. When the camera recognises the card don't forget to format it assuming that you don't have any valuable data on it.

    Best regards,


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Uhhh... Heh...

Here's the ACTUAL problem.

You have a "Memory Stick PRO Duo".

That is a SONY memory card and will only work in SONY products.

This is not a matter of compatability so much as it is PHYSICS.

This card WILL NOT work with the camera. You have to go and buy an SECURE DIGITAL card. (The kind of card depicted in the first post here.)

This camera is only compatible with SD cards. I recommend a HIGH-SPEED SD card for this camera. Allow me to paste you a product page on to indicate which one I'm talking about. (Memory capacity may vary - depending on how much you'll be willing to spend on it. I recommend minimum 2GB.)

For the price, this is an INCREDIBLY good deal. :)

Click HERE to see the product.

You should be able to find these memory cards in local retail outlets as well. Although they may cost more than getting them online. is a great place to get your computer products or electronics in general.

I hope you get this. This is an older post... Let me know.

But you can take this solution as 100% ACCURATE.

Hope to hear you got this.


Posted on Nov 17, 2007


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Posted on Jan 02, 2017

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SOURCE: Memory card locked

Hi everyone,

Here's the solution, I just had the same problem LOL!
1. take the memory card out
2.On the memory card there is a little switch (it will be the little tiny piece on the side of the card thats a different color) slide it up.

That's it!


Posted on Jan 26, 2008

  • 1 Answer

SOURCE: sd card error on canon powershot s3

I get a memory card error everytime I insert a memory card. They are not locked and I have tried 4 different memory cards and nothing works. How can this problem be fixed?

Posted on Sep 27, 2008

  • 4738 Answers

SOURCE: Loaded new memory card, and screen reads memory

I'm guessing you bought a new 4GB SDHC card. Although it looks exactly the same as a standard SD card, the format the card uses is very different. If your camera is more than a few couple years old, it's likely it was designed before the SDHC format came out. Sorry, but a SDHC card will not work with older cameras.
For older cameras, you'll need to use standard SD cards (usually those 2GB or less). But if you really want to use a 4GB card, do a Google search for 4GB SD "non HC", with the non HC in quotes. Believe Transcend makes one.

Posted on Dec 25, 2009

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