I would ask to Check for debris or if maybe some debris was pushed into the SD card slot, try to blow air into the card slot to remove any debris.
The connections on the SD Cards can get dirty, you can clean the SD contacts with a pencil eraser being sure to wipe the eraser debris away before inserting into the SD Card slot.
Which Controller did your 3D Printer cone with, or Which controller are you currently using.
The connections on the SD Cards can get dirty, you can clean the SD contacts with a pencil eraser being sure to wipe the eraser debris away before inserting into the SD Card slot.
Which Controller did your 3D Printer cone with, or Which controller are you currently using.