Brother HL-3040CN Service Manual page 347

(6) If you continue to rewrite other firmware and no file names are displayed, wait for a while,
and take out the USB flash memory and insert it again. When file names are displayed,
select the program files which need to be rewritten, and repeat the above procedures (3)
to (5) to rewrite all the selected program files.
(7) When the rewrite of the main firmware is finished, the machine automatically restarts.
(8) Remove the USB flash memory drive from the USB direct interface once the update have
finished.
(9) Next, make the settings according to the country. (Refer to
Chapter 7.)
Memo:
You can check the firmware version of the Main firmware and the Sub firmware (GDI or
PCL/PS) by printing the Printer Settings. (Refer to
Chapter 7.)
"2.4 Print out of Printer Settings" in
6-10
"1.4.16 Setting by country" in
Confidential