SD card reader not working on high sierra

Reset NVRAM may solve your problem.

Use Terminal command or apple document to reset NVRAM.

Thanks

Yes I know it seems that way but it's good to check. I've seen a great many hardware problems that coincidentally showed just after an update. It could also be a firmware problem, which are now bundled with the OS updates. Firmware problems wouldn't be fixed by reinstalling the software. So it's best to check all possibilities and be patient. If it's dire, get an external reader or connect your camera directly via USB and use Image Capture for now, until you figure out what's wrong.

Apple Menu > About This Mac then click on System Report. The first pane (Hardware) should show "Boot ROM version" toward the bottom. While you're there, check which "Model Identifier" is listed (toward the top of that pane).

btw- If you connect the camera via USB, many applications won't recognize it unless it's mounted as mass storage. Most cameras don't do this anymore, only P2P, so you have to use Image Capture to see the camera.

It looks like Apple stopped publishing standalone Firmware updates in Sept of this year, at which time they archived the page that lists current versions. At that time or shortly prior, the current Boot ROM version for the 2010 Mac Mini (4,1) machine was MM41.0042.B03, which was actually first released in 2012.

I would wager the current version today, according to SpiritPainter, MM41.0045.B00, was a very recent release, probably released with High Sierra to support the new APFS disk format. If you're running that firmware version (Apple Menu > About This Mac > System Report) it could be that's what messed up the recognition of SD cards and perhaps other removable media.

If this is the case, the likely solution is to wait for Apple to release a fix, so please let them know about it by submitting feedback Feedback - Mac mini - Apple

In Photos at the top of the second window tick Open Photos>

In Photos> Devices > *NO NAME*

If your device is not there see if you can hover over Devices > Show

Open Finder and see if it there, may need Devices > Show again

Hope this works for you.

For me (MBP 13' 2017, MacOS 10.13.3) an SD card connected via an external card reader does show up in the Finder, but when I try to open it I get a nonsensical error message and I cannot see or access the SD card content.

However, I can access the data on the SD card via Terminal and then copy the data via shell commands to the hard disk.

(So this seems to be a problem in the Finder app, not in hardware or low level OS).

Just tried the Image Capture (didn't know it existed) and it worked perfectly. Thanks so much for this, robogobo!!!

You can use Image Capture to get your photos off the card while it's inserted in your camera, connected to your MacBook via USB. Not elegant but it's the next best thing to a card reader.

Helpfull thanks for your comment.@jhon galt hope it it will fix the problem.

An SMC Reset has been known to fix that problem

One of the first things I tried was connecting the camera via usb -- no dice. Same problem, it doesn't see it. For now, my workaround is opening it on my windows computer, saving the photos on a usb stick, then plugging that into the Mac Mini. Klugey, but it works until Apple gets this thing fixed. As you can see from the comments, a lot of us are experiencing this issue, especially with mid 2010 Minis. Everything worked fine forever, then High Sierra and -- no card reader function.

We don't know that it's damaging card readers, and since there HARDWARE, how could they?

I do know, that after the install, it took extra care for me to insert MY CARD and have it seen, just

as other OS's have done the same.

I do know, that insertion of card firmly or just shy of it fully seated can cure the unfound card.

I'm glad that worked for you, but it sounds like you had a different issue. As indicated in previous comments, the internal card reader has stopped working for specific Mac owners (such as those with 2010 Mac minis who upgraded to mac OS High Sierra). This isn't a power cable issue (I'm assuming that's what you meant by "cable"), it's a conflict that's specific to a version of the macOS in conjunction with specific Mac models. And, yes, I have tried unplugging the power supply for a while and rebooted (longtime fan of the IT Crowd). My mini's internal card reader still doesn't read SD cards under macOS High Sierra.

Well of course it's a software issue -- this only happened after the upgrade to High Sierra. It worked fine before then. And yes, the Mac recognizes the card reader.

Did you click on "show all devices"?

You should boot using command-R