3D Printer not Reading Micro SD Card

It looks like some 3D printers can not read GPT microSD cards. Or SD cards formatted as exFat. You can fix the problem by converting the SD card to MBR and create a FAT32 partition on it.

Comment
byu/Extra-Load from discussion
in3Dprinting

These steps are for windows, but the idea is the same on Linux and macOS

  1. Delete the partition on the card
  2. Change to MBR
  3. Create new Fat32 Partition
  4. Use in 3D printer

Insert the Micro SD card into your computer

Next open an Administrator Command Prompt. Search for cmd, right click, and run as Administrator.

Launch the WIndows Disk Part utility with

diskpart

List the disk.

list disk

Select the Micro SD card with the following command. Replace 1 with the proper disk from the above command.

select disk 1

Now lets clean the disk. Warning! This will delete all data on the SD Card

clean

We now have a clean SD card.

Convert the SD card to MBR

convert mbr

Create a new partition to use

create partition primary size=1024

You should be able to finish this using the Disk Management utility in Windows.

Format new partition and assign drive letter.

format fs=FAT32 label="3D" quick
assign letter=E

You should be able to put your gcode files on the sdcard now.

How to view hidden EFI partition on Mac drive

Open a terminal and run the following command to list your hard drives

diskutil list

It should return something similar to the following

bobs-MacBook:~ bob$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1000.1 GB  disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            999.1 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *8.0 GB     disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS Install macOS Sierra    7.0 GB     disk2s2

bobs-MacBook:~ bob$

From above we see that the EFI partition on the main drive is disk0s1.

Make a directory for it to mount to

sudo mkdir /Volumes/TMPEFI

Mount it.

sudo mount -t msdos /dev/disk0s1 /Volumes/TMPEFI

It should now show up in finder for you to browse.

To unmount it simple eject it in Finder, or use one of the following commands

umount /Volumes/TMPEFI
diskutil unmount /Volumes/TMPEFI