It's a 'normal' light in the ceiling—with a standard 40W bulb in it. There doesn't look to be any connection problems in the fitting—and like I say with the dimmer wired 'out of the equation' the secondary switch works fine and the light is on without flicker.
i'm assuming that the old dimmer...
Hi
I've been looking to replace a dimmer switch that causes lights to flicker (even when on full) — all the replacement switches I've looked at seem to have L1 L2 and one other connector.
The switch has two sets of wiring coming into the box — earth & then two black wires and two red...