I have a conservatory with 3 wall lights operating off a single switch.
I replaced one of the wall lights, and ensured it was wired correctly. However when the power is turned back on, it doesn't work. When the light switch is turned on, the remaining two lights still turn on as normal.
What is it that prompted you to change this light fitting?
If it stopped working, and that is why you changed it then you have either a cable problem or a bad connection.
If you changed it for another reason (say the light got damaged) and was still working until you changed it, then since it should only have 3 connections you have connected it wrong or just a bad connection.
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