I am not sure what you mean by that. Aren't the brown wires + and the blue - always? I have plugged some of the non-working lamps into spare slots on the working distrbutors and they work fine. Should I try switching the blue and the browns around?
They are almost ready made. You have to plug each lamp's leads into a plastic connector with + and -, the led driver is already connected to the distributor, which has six connections.
I have installed three sets of B&Q LED downlighters under my kitchen cabinets. Two sets of 2 and a set of 5. One set of 2 are supplied by a cable which is powering a set of 2 LED downlighters inside a cabinet and the set of 5 is supplied by a cable which is powering a set of 4 LED downlighters...