Please be noted that the firmware and the slicing software need to be updated all together!
Step Guide of Anet N4 firmware update:
A. Download and copy the firmware update files N4_V1.09.bin on your flash drive.
B. Click “Printing” and select N4_V1.09.bin on the files list.
C. Click print and it would pop up a message “Whether to update firmware?”. Click “Enter”.
D. Wait for update until the firmware information show version V1.65.