The ceiling room light flickered and then went out. I checked the bulb on another light and it is working. I tried another bulb but the light still doesn't work. Fuses not tripped. I checked the connections of the bulb holder and at the ceiling rose and they are all ok. I connected another bulb holder but still no light. The room switch controls only this light. When I switch on, the brown wire becomes live but the blue stays dead even when a working bulb is used. What else can I check?