how to reset the message replace drum on panasonic laser fax model kxfl 612 machine.?

the drum unit is producing excellent copy quality , opened shell of cartridge no chip or any thing in …i guess should be a code to set the same ………..i know press menu then ash then 9000 then star u get sf= that is the entry to reset ………then punch the reset nos and printer for heater reset…..so should be something for drum reset………………