We moved into a new house recently, which has cuplights under the kitchen cupboards. There was a note to tell us where their 'mains' switch is (hidden away at ankle height at the back of a cupboard) but turning that on doesn't make the lights come on. I'm assuming there must be another more convenient switch on or near the lights themselves, but I can't see it. There is a transformer (pictured) but I can't see a switch on that. What am I missing?