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I'm using Lion (10.7.3) on a mid-2010 MacBook Pro. I just got a 32GB SD card and formatted it with my camera. I'd like to transfer some files onto it from my computer, but the card seems to be read-only when I access it in Finder. And in Disk Utility, all options are grayed out so I can't reformat the card.

I found this KB article which seems to describe the problem, but the solution doesn't work:

$ diskutil partitiondisk disk1 JHFS+ newdisk 100%
Started partitioning on disk1
Unmounting disk
Error: -69877: Couldn't open device

What's going on and how can I get around it?

Edit: yes, I already checked the physical lock switch on the card!

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I was just going to suggest the lock switch too... but if that's not it, can you click the Partition tab and tell us how the card is currently formatted? If I remember right, OS X can read but not write an NTFS-formatted device, but it seems unlikely that your camera would have formatted the card that way.

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It's shown as "MS-DOS (FAT)" as in the first screenshot. – jtbandes Feb 14 '12 at 15:52

I encountered the exact same thing... the issue was that the lock switch was getting flipped when I pushed the card into the slot and it would flip back to unlock when I pulled the card out, lol. I was able to get it in without the switch flipping by pushing it to the opposite side of where the switch is.

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The only other time I've seen this is when the card was locked. Did you accidentally hit the lock mechanism on the corner of the card?

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Forgot to mention that I already checked this. Thanks though. – jtbandes Feb 14 '12 at 15:50
up vote 0 down vote accepted

Unfortunately I'm not sure what the problem was — after some more formatting and fiddling around, the issue resolved itself.

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protected by Daniel Sep 23 '12 at 5:11

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