Progress….nearly there!
Thank you both
@Millemis, I found A.SETUP, although to do so, I found it by selecting another source (not CD) before pressing standby+list
@Guy, my Beo4 indeed has an AV button in the middle of row 2, however that doesn’t even make it display AV! Anyway, having pressed A SETUP > GO, it offers SOUND, BASS, TREBLE, LOUDNSS, S. STORE, with balance hiding somewhere.
Fortunately, having driven it full left on my 5500 master control panel, the reset function still works.
Any clues where Balance might be hiding?
Thanks to your help, I’m making progress and have even managed to add PHONO to the LIST options.