Sunlu does not have the most organized repository, but official files are available.
Insert the prepared MicroSD card into the printer's card slot.
Ready to take the leap? Gather your SD card, head over to Sunlu’s official download page, and give your printer the software upgrade it deserves.
The printer mainboard remembers the last flashed filename. Rename the file to something completely different (e.g., sunlut3_v2.bin ) and try again. Sunlu T3 Firmware Update
The V3.43 update (the most widely discussed stock release) brings three documented improvements, according to Sunlu’s official release notes:
Requires purchasing and setting up external hardware (like a Raspberry Pi); steeper learning curve. Prerequisites: What You Need Before Starting
Navigate to > Store Settings or look for Initialize EEPROM / Reset Factory Defaults . Sunlu does not have the most organized repository,
Copy the .bin file directly to the root directory of your formatted MicroSD card. Do not put it inside any folders.
If you attempted a screen update that failed, the printer might be stuck on a logo screen. A fresh firmware flash is the only cure.
Before updating your Sunlu T3 firmware, make sure to: Gather your SD card, head over to Sunlu’s
Download your chosen custom Marlin .bin file from a trusted community repository (such as GitHub).
With the printer still off , insert the microSD card into the printer’s card slot (not the USB‑host port).
Ensure the file ends strictly in .bin . Make sure the card is under 32GB and successfully formatted to FAT32. Try renaming the file to something short, like firmware.bin . Blank Blue Screen (Bricked State)
These advanced features counteract the physical vibrations of your printer. Input Shaping smooths out ghosting on vertical walls, while Pressure Advance (or Linear Advance in Marlin) prevents bloating at the corners of your prints.
Turn off the machine. Remove the SD card, re-format it completely, re-download the firmware file, and try the process again using a different SD card if possible. Advanced: Transitioning to Klipper Firmware