I have a 128GB SDXC card for video. It reads in my MacBook Air but not in my iMac...the newest version, 2019, just purchased last month (July, 2020). My old iMac read this card also. What is the problem with the new computer not reading the card? The card obviously works fine on other equipment.
Run Disk Utility (Utilities folder in Applications folder) and set View (Top-left) to "Show All Devices".
It should show the SDXC card in the left column with its volume indented below it. Select the volume and look for the volume format near the top of the window.
If it shows "Mac OS Standard" of HFS, not "Mac OS Extended" or HFS+, then that's the problem. Catalina dropped support for the older volume format that was replaced in 1998, probably because the code to support it was 32-bit.
Run Disk Utility (Utilities folder in Applications folder) and set View (Top-left) to "Show All Devices".
It should show the SDXC card in the left column with its volume indented below it. Select the volume and look for the volume format near the top of the window.
If it shows "Mac OS Standard" of HFS, not "Mac OS Extended" or HFS+, then that's the problem. Catalina dropped support for the older volume format that was replaced in 1998, probably because the code to support it was 32-bit.
Hi Sonya7iiiwithiMac,
Thank you for posting in Apple Communities! Sounds like you new iMac isn't reading your Sony memory card, do we have that right? What macOS is currently installed on your new iMac? How about on your MacBook Air and older iMac? Are you using a memory card reader? If so, is the reader compatible with the macOS currently installed on your new iMac?
About the SD and SDXC card slot on your Mac
Are you able to have the SDXC card read when booted into safe mode?
How to use safe mode on your Mac
You may need to check out Sony's support site for information about compatibility: Welcome to Sony Support
Hope that helps!
iMac won't read Sony SDXC M 128GB cards?
