Hi all,. .And as I understand the 'magic door', you can't walk through it without it making some sort of response, but only 'beeps' if that response exceeds the selected threshhold, so, with that in mind, how come they don't detect an unserviceable detector right away?. .Also, the LEDs down the side, indicate at what height of the person that any magnetic anomaly was detected.. .Cheers!