My 2013 iMac running Catalina can’t read the new SanDisk 64GB SD card. I found that the card doesn’t up in Finder and won’t mount in Disk Utility. What should I do?
Since your SD card shows up in Disk Utility (although is unmounted), it indicates that there are no connection issues. You can manually mount your SD card in Disk Utility.
If the SD card is not mounting on your Mac, it shows that the SD card is corrupted. You should reformat the SD card to repair it. Have you stored any data on the SD card? If you have, recover data from the SD card with a data recovery tool like iBoysoft Data Recovery for Mac. Or else, all your data will be erased after the reformatting.
iBoysoft Data Recovery for Mac is a professional data recovery software that can rescue files from corrupted, unmounted, and inaccessible storage devices like SD cards and external hard drives.
Simply download, install, and open the application on your Mac, select the SD card, click Search for Lost Data, preview the files after scanning, and click Recover to restore files from the SD card to a different destination.
Your new SD card is not showing up on your Mac because it is not initialized. Usually, a new SD card is not partitioned and assigns a file system for data storage. That’s why you find it not showing up in Finder and in an unmounted state in Disk Utility.