SD card reader not working after upgrading to Lion.

I have the same problem on my 2010 13" Macbook Pro while running Lion. I notice that when running Bootcamp with Windows Vista Business the SD card works just fine. So I reinstalled Lion and Lion still would not notice the SD card.

I had this problem with my early 2011 MBP (the SD card not working). I tried everything: repair the disk, reset the PRAM, yada yada. The card reader showed up as a device, but no card would recognize in disk utility. It wouldn't even show up in the disk utility if I booted off the install DVD.

So, I started thinking about this poor mac. It's been around for 18months or so and has spent it's life in my laptop bag when not in use. The slot has no door, and I can only imagine what kind of crap has gotten in there.

SO! Here's how I fixed it!

1. Blow out the slot - your mouth, canned air, whatever
2. Fold a post-it note so that the sticky stuff is on the outside, and it's about as wide as the slot
3. Slide the post-it into the slot so that the sticky stuff rubs the pins and casing
4. Do the same thing with the non-sticky part to clean up any post-it residue
5. Blow into it one more time to make sure it's all happy

And, now, the disk shows up with no hesitation. I guess inserting the card over and over wasn't enough to really clean the contacts. So, anyway, hope this helps all of you. <3z

This solution apperently works? I just tried it and WALLA my card reader is working again!

It's just that I don't know for how long? I guess the contacts inside the card reader get dirty very quickly?

I am really surprised how it worked but who cares since it works 😀 I am really appreciated for your solution danheberden 🙂 I did it as described and magic happened right away. My sd card wasn't working after I upgraded to Lion but now it works. I was installing Lion couple of times and reading endless threads to find a solution for it. This is the only solution worked for me. Once again thank you danheberden.

Worked for me too - post it note went in, tiny clump of fluff came out, card reader worked again. It had been out of action for months and I had given up on it and started using a USB adapter to import my photos. Thank you. Little things like that can make someone very happy.

I should also mention the following that helped:

My specific card, a CENTON 64gb SDXC card, had additional issues. It only worked sometimes when sliding it in and pulling up on the card (thus, forcing the card down against the pins).

I think some cards aren't exactly the same size or thickness and our card-reader, well, is a piece of ****.

So I did, and do, the following and now it works nearly every time.

1) when sliding it in, make sure the card is against the side of the sd-slot that is closest to the headphone/mic jacks. There seems to be enough play/tollerance that if you slide it in and the card moves towards the usb ports, the pins might not make contact appropriately.

2) if still having trouble, place 4-8 layers of thin tape (I used scotch tape) on the front of the card (same side as the pins, but the top of the card) to make it a little bit thicker. I also added the same amount of tape to the rear side of the card on the underside to lift it up (leveraging it against the pins, hopefully). Regardless of what you do, the point is to get the card to fit more snuggly against the pins. I should note that I use this card in my canon dslr and it fits just fine with the added tape.

Many thanks danheberden, your solution worked for me too. How simple was that!

Sounds like some in this thread are having success after cleaning their hardware. For those trouble shooting I still don't think its hardware. All my cards and readers work fine on my G5 Tower running 10.5.8 but these same cards and readers don't work on my MacPro Tower running Lion 10.7.5... although it used to work on Lion up till recently. Hope this helps find the ultimate solution in guiding the thousands out there with this issue within the dozens of threads on here!

This has bugged me for a while. I use CF cards so have not bothered until I wanted to load photos onto an SD card for my digital photo frame.

I tried all the fixes suggested only to find the SMC, PRAM, XQuartz etc. did not work. What worked was cleaning the port. I used the mixing spatula from an araldite glue kit, kitchen roll (slightly rough surface) and ethanol. With the Macbook Pro swithed off I worked the solution around the pins. I let the ethanol evaporate and powered up and it is nor working again.

I don't know that it would be dust as my laptop resides in a neoprene case when not in use. My guess is that there is oxidisation on the terminals.