How to reset 'Inkbox Full' notice for printer BROTHER DCP-T720DW

Steps how to reset the inkbox full notice for Printer Brother DCP-T720DW Step 1: Power off then power on the printer Steps 2: Press 'Menu' and Mono button then press 4x for the 'Arrow up' untill Machine Err 4600 displays on the screen. Steps 3: Press arrow up until displays the number 8 then press 'OK' it should display the MAINTENANCE 8 on the screen. Steps 4: Press arrow up again until displays the number 0 then press 'OK' it should display the MAINTENANCE 80 on the screen. Steps 5: Press the 'Mono' button until you find the 'PURGE COUNT' on the screen then press 'OK' button it should display the PURGE counter on the screen. Steps 6: Enter the reset code '2783' by pressing the 'ARROW UP' button until the purge counter set to zeros.