Naim narcom 5 and AV switching

Hi everybody, sorry for the newbie question but i can’t seem to figure put how to switch to any of my sources on my Nait5si, especially the AV channel. The only buttons that seem to be working on the remote are volume and mute. I’ve tried going into prog mode by keeping the prog button pressed for like 20 seconds but to no avail. Help !

Touch the black “Pre” button, then you press either the relevant input number button or advance with the < > arrows to select the input button you need