SD card reader not working on iMac

Ok I know this is an old thread bit I just had the same problem and found that it was a dirty card switch inside the reader slot. I just blasted it with a couple of shots of compressed air from an aerosol duster can and its working fine now. Its a hardware fault not a software fault. The switch is at the topside inside the card reader if its an imac. Hope this helps anyone with the same problem.

The card reader on my MacbookPro stopped working this week. I've tried the rebooting, using a different card, all to no avail. The cards are fine as I can read them using the adapter for my iPad. So, I'm assuming a hardware problem. I'll try the compressed air and toothpick method.

If previously installed GOPRO HERO software - uninstall it and try.

My SD Card slot also wasn't working so I tried freeing up the internal bits and hey presto, it now works again. I had never even thought of the problem being mechanical. With all the various other problems that I have with my iMac I have lost so much faith in Apple. Give it another 10 years and they'll be viewed with the same disdain as Microsoft.

If anyone is having problems with an SD card reader, or any connector for that matter, a touch of WD40 on the connector first then inserted in an out of the mac a couple of time should revive any connections. Unless brutal force was used to chew out the connector typically it is just contact dirt that interferes with the voltages, similar to crackle on a dirty volume dial. Additionally on new unibody macbook it seems to me that the backplate helps to ground some of the connectors or at least pushes on a series of small buttons lined along the connectors. Its worth making sure its on tightly near to the connectors else one thing might start talking to another or simply become mute and not talk at all. Hope this helps 🙂 Its revived many connectors of mine countless times

Just to add this works on USB, Firewire or any port, just make sure you dont overdo the WD40 and give it a few seconds before inserting just to rule out the possibility of dripping, itll evaporate pretty quickly

I was having issues with my Macbook Pro (2012 model running 10.7.5) SD card slot. Originally it was a software issue for me, stating that my laptop didnt have a SD card slot but after doing all the OS X updates, the System Report (About this Mac > More Info > System Report > Hardware > Card Reader) had recognized that it had one.

Tried putting a 4GB Fujifilm SD, 1GB & 4GB Sandisk SD, and none would show up under devices or on the desktop. I tried all of the solutions above and none of them worked. Then I read the posts about the compressed air and WD40. I wanted to avoid putting any liquid in my laptop so I figured the air would work. Unfortunately I didnt have any compressed air sitting around. I opted to get a flashlight and took a look inside the SD slot. TONS of dust and hair particles. I got myself a dental explorer (my mother works for a dentist) and used the hook from it to pull the dust and hair out while being mindful and very cautious of all the metal prongs inside. Then I blew into the slot twice once I removed all the dust, and viola! It works again! Even restarted the laptop twice and it still works.

Obviously not everyone has a dental explorer lying around so your next option could be bending a paper clip into a sort of C shape and use that! Just make sure you unplug and turn off your laptop or imac and be VERY CAREFUL WHEN POKING AROUND INSIDE. You dont want to bend any of the connectors. Let me know if this helps anyone!

For those continuing to trouble-shoot. I have suddeny run into this same issue with my old reliable MacPro 1.1 tower running 10.7.4 using a USB'ed card reader. All my cards and readers work fine on my G5 tower running 10.5.8.

Strangely, this worked for me. The card reader would work if a sd card was inserted, and the iMac restarted. However, if it was properly ejected, then reinserted, the card would never mount. The little flexible tooth flosser stick did the trick.

Thanks, Roger

I have the same problem on my 2 month-old MBP.

Observation 1. SD card reader sees the card after reboot, but after it is ejected and reinserted, does not recognise the card anymore until the next reboot.

Observation 2. MBP takes about ten minutes to reboot if my SD card is not inserted, but takes about 10 seconds if my SD card is inserted.

This is what I did to troubleshoot the problem.

Step 1. Reinstalled Mountain Lion

Step 2. Verified that the SD card reader is working properly again

Step 3. Updated the new software updates (includes OS X update, update of camera RAW)

Step 4. Verified that the problem recurs

Repeat steps 1 to 4 to reconfirm observations.

Definitely something to do with the June updates.

Have encountered the same issue with the latest OS X Update 10.8.4. SD card only mounts after a system restart. Clearly an Apple issue. Awaiting a hotfix.

I was also having this problem and I found a different solution. Inserting the SD card after locking it with its dedicated switch and unlocking it again fixed it.

Guess what? I was having the same problem and you know what finally worked after trying all the suggestions?

I got a air duster can and put the straw near the slot. Straight up old school Nintendo style. I'm not joking.

Works fine and shows up on my desk top now. Man... 30 years later and the same trick still works.

I was having the same problem. I took my MBP (early 2011) to the local Genius Bar. They replaced the logic board (under extended warrantee). Works without a hitch now. If I didn't have the warranty it would have cost me over $600--I certainly would have tried all of the recommended solutions here first before laying out that kind of dough.

I blew into the SD reader like it was Super Nintendo and it worked for me