1. Download the firmware update file for your model.

2. Do not rename the firmware update file.

3. The USB flash drive must be formatted using the FAT32 file system. Other file systems, such as exFAT or NTFS, can't update the firmware properly.

4. Copy the firmware update file to the root directory of the USB flash drive. Do not put it in a folder.

5. After updating, delete the firmware file from the USB flash drive to avoid accidental repeated updates.

6. If you have followed the above steps and are still unable to update, please use a different USB flash drive.

1. Turn off the printer power.

2. Download the correct firmware file from the website and copy the "ChituUpgrade.bin" file to the root directory of a USB flash drive in FAT32 format.

3. Insert the USB flash drive into the printer's USB port.

4. Turn on the printer. The printer will automatically search for the firmware update file on the flash drive and start updating.

5. If you see a progress bar, it means that the firmware has been updated. Wait for the update to finish, and once you can access the printer interface normally. Refer to the instructions in the firmware update document to update the firmware again.