Built in SD Card Reader:

  • Vendor ID: 0x05ac
  • Product ID: 0x8406
  • Revision: 3.00
  • Serial Number: 00000000AP05

SDXC Card:

  • Capacity: 61.92 GB (61,924,704,256 bytes)
  • Removable Media: Yes
  • BSD Name: disk4
  • Partition Map Type: MBR (Master Boot Record)
  • S.M.A.R.T. status: Not Supported



  • Capacity: 61.92 GB (61,923,655,680 bytes)
  • BSD Name: disk4s1
  • Content: Windows_FAT_32

Yosemite cannot mount the above card, Disk Utility shows disk4s1 in grey, with Mount Point: Not mounted

Is there a fix?

  • 2
    a 64GB card really ought to be exFAT, not FAT32. I'm not certain OS X can handle FAT over 32GB, but I can't find a hard reference for that.
    – Tetsujin
    Apr 30, 2015 at 7:27
  • It's possibly a badly formatted card. I've seen tons of examples of poor-quality cheap cards coming improperly formatted. Try using Disk Utility to repartition and reinitialize the SD card. If the card isn't a name brand (and even if it is - counterfeiters love to imitate name brands) I'd highly suggest you thoroughly test the card by filling it all the way up with data and then trying to access some of the first few files you wrote before trusting the card.
    – fdmillion
    Sep 15, 2015 at 7:00


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