Well, after looking at the documentation it appears that since there's no real-time display on the camera monitor, that there is no vid signal present until playback - duh! I guess if I'd thought about the fact that there's a mirror in the way I could have answered my own question... :
Mabye something OLY could add in the future: mirror lock-up with real-time vid output when under AC power. Would be great for technical photography.
Thanks for looking anyway!
Regards,
ADG