sd card on iMac not working with el capitan

I have no Adobe products on my iMac, never have. I used to have the Flash Player, but I dumped that a long long time ago. Flash will still play, under Chrome. It is possible that some applications do something that messes up Apple's USB software, but I think it is a problem with how Apple handles sleep and USB hardware initialization. That stuff is hard to get right and clearly they broke it.

We have many people on this forum report PRAM reset worked, I always figure, just wait as it always works after a power cycle/restart. One person took their computer in for repair and says the replacement hardware fixed it, but I wonder how well they tested it. Yeah, maybe my 7 year old iMac has a hardware problem, but one that goes away on a power cycle or reboot? I think not. It is software. It is El Capitan.

It isn't even worth identifying a culprit anyway. SDHC cards should work. Every time. They used to work in all OS X releases since my iMac was made, until El Capitan. I don't even remember what OS version it came with.

I have had the SDHC card problem since El Capitan on my iMac and newer Mini and have reported some improvement with 10.11.4 and no change with 10.11.5. My iMac has been through a few sleep cycles since I powered it up Sunday and it is ignoring my just inserted SDHC card as expected. I'd like to think that Apple has a fix all set for whatever the next release of OS X is called.

I've seen Apple introduce and fix issues over the years. I've never seen a problem like this where something that should work doesn't and it doesn't get addressed. I am sure the fix is known, but not important enough for an out of planned release cycle correction.

Made a reply to the first post to see if anyone still subscribes and has reports on 10.11.6 impact on the problem.

It has only been a few days, but I've tried 10.11.6 on reading and writing SDHC cards every day since. Two different cards. So far, no problems. This 2009 iMac has been on overnight sleep each time, sometimes logged out and sometimes not.

I think the cards are recognized faster and eject faster too, but I have no evidence.

Anyone else see improvement? This release is somewhat unexpected. Daily testing continues.

Cheers

Nope, 10.11.6 broke SD detection again. So quite the opposite actually (late 2009 iMac). 😢

However, zapping the PRAM again restored detection. Sigh!

Well, I spoke too soon. Performing my now daily "does it read check" on the SDHC reader on my also 2009 iMac. It mounted quickly and then shortly later self ejected. Well, not physically. The old "not ejected properly" message. So, Apple gets a big Thumbs Down on 10.11.6 from me as well. I was able to read and write for several days, but not today. So we'll get to see what Apple does to disappoint when Sierra comes around. Low expectations. I also get the magic spinning color wheel whenever I create a calendar item in Calendar. As expected, no fix to that in 10.11.6. I haven't bothered to zap PRAM in ages. I tend to think it as magical as rebooting.

I was smart enough to never upgrade my iMac and Macbook Pro at the same time, and have been using my laptop to download photos from an SD card. Then while I was reading this tale of woe somebody mentioned El Capitan works if you just connect to the camera instead. Well sure enough it does and I'll just stop even trying to use an SD card in my 2009 iMac. I've been an Apple fanboy for at least 18 years, but this SD card screwup is a shameful Windows type of a mess.

On my late '09 27" iMac running 10.11.6, a faster card (Sony 70MP/S U1 10) triggered "The disk you inserted was not readable by this computer." when inserted in internal slot or USB 2.0 reader, but mounted fine when inserted via a newer USB 3.0 reader (Kingston MobileLite G4). Older, slower cards no longer mount in internal slot, but will mount via USB 2.0 reader.

Eureka! I just successfully un-stuck the switch with a piece of stiff thick nylon fishing line on my late '09 27" iMac -- and all of my cards are mounting again. All it took was poking the probe about in the top rear of the slot for about 10 seconds. Mystery solved! Thanks so much.

I have to do the PRAM reset over en over again. Works initially but at irregular times the SD card is lost again. This is really becoming an annoyance. Problem are not the SD cards, they work fine on Windows pc's etc, but not on El Capitan. Before El Capitan no problem at all. The hardware tests show no problems so it appears not to be a hardware problem, but a software Capitan issue. I have a late 2009 iMac 27". As I am experiencing more and more problems with El Capitan and Apple's support towards it, my new computer will very problably not be an iMac again but I will be returning to Windows or good old Linux.

Anyone subscribed to this thread have bad experiences with Sierra and SDHC cards?

So far, I have had no problems, but it has only been three full days. No self ejects and no problems after sleep cycles.

I am hoping that Sierra has addressed the problem, but I want to see more test results from the community.

Any negative results with Sierra are of primary interest.

So far, so good.

Otherwise, Sierra is a snooze for me.

So far, no reason to miss El Capitan.

I have IMAC 25 mid 2011 with intermittent SD mini Card mounting problems, since I installed El Capitain. Last week stopped working..... Read all blogs, tried every suggestion and nothing! Bougth an external unit, that could read the micro SD, but not the mini SD !!!! ?????

Finally I turned on in recovery mode, with, by mistake, SD card in place and it was recognized in Disk Utility!!!! Than I ejected and changed the SD Card, it wasn’t recognized.........So I did everything again and was possible to mount the cards in both units!!!! Restart the IMAC and could work normally with the Mini SD Cards, in both units.

Not sure but I think that every time I eject ⏏ the card, the OS disconnects the unit and don’t recognize the next card!!! Could be??? Now when it occurs, I first insert the SD Card and then turn on IMAC.

Since I installed Sierra the SD problem seems to have finally solved. However, although after repeated stop the card is no longer expelled, sometimes I get the message of incorrect ejection, but the card remains in place. I think I can be happy, after all the tribulations ever since I installed El Capitan!

Just moved up to Sierra and this is still not solving the issue on 14 school imacs and macbook pro's, will try the airs next but even our external usb card readers fail now. All of our graphics classes and film classes are grinding to a halt trying to offload portfolio work and HD film for editing. This is simply unacceptable. ....made worse by the dismissal of the problem as a rash all over the internet. Why Why WHY is it impossible to get a signed driver that accepts external readers? I think we are going to have to run Ubuntu on these off a live boot stick, if I can get around the UEFI madness that is Apple's non standard approach to everything.

.....oh wait solved it...... A 10 year old Win PC Laptop just did the job in about 30minutes (lots to upload), the macs are still 100% failing (and yes I followed every PRAM and other eccentric trick or "solution" on this 12 page fiasco of tech support discussion board....no success!).

For those reading this, skip Sierra.... I'm sure I will have to repair every Adobe app for the next month now that I updated in the dashed hopes of getting basic hardware function out of ANY SD card.

Don't bother responding....there is and never will be a solution....its a unicorn....stop pretending ...buy a lenovo

I confirm that since I installed Sierra my SD card reader works even after the stop, although it still sends messages of incorrect expulsion. Is there anyone else who is having the same experience?

Did as you suggested and still have to problem. No external memory showing in Finder when using the build in CD card reader.

Same here. PRAM reboot work just once