Cant write to SD card?

TacoLord187, how did you get the arm to stay there? Presumably it sprang back? I've got the same problem, works fine in the iMac, but in the Macbook it is read only.

Well, the arm seems to spring in and out no problem, however found this on another thread https://discussions.apple.com/thread/4261016?answerId=19452639022#19452639022, and it solved my read-only issues. Can now read and write throught the SD card slot. Moving the lock slider to an intermediate point did not work for me.

no, slider is in read/write position (towards the computer). Sliding it in until just before (1-2mm) it stops allows read/write. Anymore and it is read only.

Do you know if that arm is set up so arm-out is read only, arm-in is read/write? By out I mean sticking out into the SD slot, it I mean pressed in towards computer.

I just had this problem, the way I fixed this is by blowing hard 😀 into sd card reader (MBP early 2011).

I noticed that apple ***** at these small things - my thunderbolt port is flickering, my audio out became mono, annoying things happen to sd card reader, usb ports like to disconnect when I push my mbp a little 😟

I have the same problem. But when I read the SD card in a Windows 7 virtual machine mounted on Mac OS X, everything is solved. So this cannot be a hardware fault. It's a software (OS) problem with Mac OS X. Apple, please look into this problem and fix it asap. I really don't like starting the virtual machine everytime when I want to modify the content on my SD card.

I have a similar problem where my Mac is unable to write to or delete files from an SD card in the card reader. Another post from 2010 mentioned changing the "Lock" switch to be halfway between locked and unlocked - and that worked for me! With it in the halfway position, I can now do anything on the SD card. Seems like the reader in MacBooks needs some work.

I just had this problem: SD cards would appear as writable in a cheap reader but not from the SD port on my iMac.

Pushing the card in and out of the iMac SD car slot three or four times seemed to fix it.

I had the same problem with my MacBook Pro 15" mid 2009.

The problem is a dirty or little bend write protection tip/arm on SD card slot.

I had disassemble the motherboard and clean the tip/arm on the side with alcohol and compressed air. Now it works! Not perfect but now I can write two out of five times I put in a SD card.

I am also having this problem. I have several new SD and they all are read only at this point. I card that stopped working first had the lock/unlock arm come off. So I am wondering if piece is stuck in behind the arm in the computer. I put an external SD card readers and new card works in SD reader. New SD card will not work in the computer SD slot. Any body ever dug this deep in the machine? I have replaced memory, processors and disk drives, but never gone this deep into it.

I'm having this same problem pretty much as described above, except that I did plug it into the card reader on my Epson Printer (hooked to my Macbook Pro (2012) via apple monitor USB and into the Macbook USB.

Same problem. Both SD cards I'm testing with are only readable and I can't seem to do anything to effect change. They are both formatted via a Nikon and one of them I just reformatted (no fancy options to choose from in-camera, just plain "FORMAT".

So this seems like a software issue to me unless a faulty arm inside the macbook is somehow causing all SD cards (even through a USB) to also misread the write status.

Very perplexing and especially based on how common this issue seems to be (there are lots of similar threads) and that no one has identified some kind of missing file or patch or something.

This computer is relatively new to me and it had one version of OSX and the I restored from my old Macbook Pro (late 2010) after updating it to Mountain Lion. So could the restore have brought over some incorrect file from the old hardware/software configuration?

I don't know enough to answer that.

p.s. The reason I need to write to the card is that this is how to update the firmware. It seems I have to do it. Also, one should be able to write to one's men cards as a rule.

This is so frustrating

Thanks for any advice from anyone.

"I removed the back of my Mac just now, and looked at the small gap on the logic board where you can see the SD reader.

On the right hand side (Closest to the first USB port) there is a small silver arm that you can see. I simply pushed it back in with a paper clip, and now my SD reader recognizes the same card as Read/Write."

THANK YOU SO MUCH I bought myself a JetDrive and noticed that ALL SD cards put in would be read only, I tried so many things including resetting SMC, PRAM, alcohol on kitchen towel, blowing inside, inserting cards a little skewed, wiggling, lock switch to middle position, NOTHING worked.

I would like to share exactly how to fix this the way I did, in case anyone else has this issue. For a long time I tried to bend the arm without anything plugged in, however, the arm didn't budge when i poked a paperclip at it. It was too recessed into the card slot enclosure itself to move. I plugged in an SD card in lock position, the pin popped out a little bit, and I managed to get the paperclip to push the arm. Booted up, plugged the JetDrive in and viola!

For future reference, POKE HERE with card inserted, the metal should be accessible because the card lock switch will shift it out.