Insert the SD card into the (not the mainboard slot). Turn the printer ON .
Use the DWIN_SET folder provided in the firmware download.
Turn off the printer, remove the SD card, check the file format (must be FAT32), and try again. Sometimes changing the file name (e.g., from firmware_v3.bin to update.bin ) can help, although usually, the .bin extension needs to be preserved.
Sunlu usually provides older firmware versions on the same page. That means you can downgrade if the new version causes unexpected problems. Keep the previous firmware file handy before you flash. Sunlu T3 Firmware Update
Newer versions address issues with jam detection and LCD refresh rates .
John's curiosity was piqued, and he quickly logged into his Sunlu account to learn more about the update. After reading through the changelog, he decided it was worth updating. He downloaded the firmware file and prepared his T3 for the update.
The screen will remain blank for roughly 10 to 30 seconds. This is normal behavior while the bootloader installs the new code. Insert the SD card into the (not the mainboard slot)
When the update is complete, the printer will either reboot itself or display a message indicating success.
The screen will stay blank for 10–30 seconds while the board updates. Once finished, the main menu will appear. Post-Update
A popular pre-compiled version with 5x5 Bed Leveling and higher temp support is available on Printables by Kaot93 Setup & Optimization Anson Liu's technical blog Turn off the printer, remove the SD card,
Insert the prepared MicroSD card into the printer's card slot. Turn on the power switch.
Note: Use the method your board and firmware require. SD/USB are the most common.
Updating your firmware isn’t just about having the latest version; it's about stability. Common reasons to update include: