It´s hard for me to belive that there are devices without the krackling display:
here is a video taken with my z1 compact from my 4th z3 compact - you can hear a sound right after pressing the panel.
I´m so unhappy. It´s not a problem in function but this is anoying!
Mine dose the same but not so loud,try to push the panel and then the back,you would see that the back its doing that not the panel(at least mine its like that).