I’ve got a set of 7 spotlight bulbs in my kitchen, mostly MR16s. Once of them had been intermittently fading on and off (after being switched on for a while) so I tried changing the bulb and the new bulb didn’t work at all. I figured it might be the transformer, I’ve changed the transformer for a couple of the others in the past, so I bought a new one and fitted it but still no light. I decided to test the ceramic holder by switching it into one of the working spotlights and it still worked so I know the holder isn’t faulty. If it’s none of those what might it be?! Thanks!