SD card not recognized

Step 1: Basic inspection (SD card and slot)
Card type: The motherboard supports MicroSD cards (TF cards). Make sure the card fits securely in the slot.
Physical contact and cleaning:
Gold finger oxidation: Remove the SD card and gently wipe the metal contacts (“gold fingers”) with a cotton swab dipped in a small amount of anhydrous alcohol. Wait until it’s completely dry before reinserting.
Slot condition: Check the SD card slot on the engraver’s mainboard for physical damage, dust, or debris. You can use an air blower to clean it carefully.
Poor contact: When inserting the SD card, ensure it is fully inserted and that you hear or feel a slight “click” indicating it’s locked in place.

Step 2: File and engraving settings inspection
If the SD card is recognized but files cannot be read or “access is denied”:

File name and format:
File name: Use simple English letters or numbers. Avoid Chinese characters, special symbols (like @#$%^&), or long filenames.
File format: Make sure the file format is supported by the engraver’s mainboard — it should be .nc, .gc, or .gcode. Check that your laser software (e.g., LightBurn) exports the correct format when saving to the SD card.

File path:
Do not place files in nested folders. It’s best to store G-code files directly in the root directory of the SD card, as the firmware may not support reading from subfolders.
Encrypted files: Encrypted files cannot be loaded.

G-code content:
Sometimes a file may be corrupted or contain special commands that the engraver’s firmware cannot recognize.
Troubleshooting: Try using a very simple, newly generated G-code file for testing, such as one that only engraves a square. If the simple file is recognized, the original file may be the issue.