Hi, Probably too late on this one. But I have a Russel Hobs Microwave. It’s 10 years old and does an ok job considering the company / price. It is very simple to stop it beeping. However I must stress you do this at your own risk. (unplug it, don’t lick any wires blah blah). Mine was on the right hand site at the front as you remove the cover. You will see a 22mm Buzzer (). Its mounted to the PCB. with a small pair of wire snips, just cut one of the connectors. Job done