Intermittent light problem

[expleto]

I have a strange problem with a few of my lights. At the back door there is a double light switch, (A + B) A feeds two bulbs, B feeds one.
A single live wire comes down to the com on A, and bridges to B.
No idea what happens to the neutral.

The light worked to my knowledge for atleast 7 years, then for no reason it started to do the following random things when switched on.

90% the time=no effect.
8% light would flicker but no effect.
2% light will come on and works until turned off.

This applies to both A+B, strange thing is, once one of the switches goes on, you can turn the other on and off 100% of the time, dosent matter which order you do it in.

I have changed the switch to no effect, bulbs are energy saving, but i have tried normal to no effect, my best guess is that somewhere along the live before the switch a connection is loose, but the intermittent nature of it is confusing. Anyone got any ideas before I rip the cieling down and run new cables in ???

 

[Diyisfun]

The switch only switches the live supply, neutral straight to light fitting.
Have you you checked for bad connections at the light fitting?.
Im not an electrician,

 

[expleto]

When I said No idea what happened to the neutral, what I meant was that it was tucked up in the roof and had no idea as to how it was layed out, because I cant see it. I have checked the light fittings, but not changed them, 'A' has two bulb fittings which are old, 'B' has a brand new fitting, (fitted when I put the new switch in, after the problem). I didnt change any on 'A' as im fairly sure the problem is further back, any ideas on how this could happen would be useful, could a loose screw in chop block cause the problem, Im not convinced due to the fact that, once one works, you can keep it on for days. Thats not consistent with a loose connection.

 

[Diyisfun]

could a loose screw in chop block cause the problem, Im not convinced due to the fact that, once one works, you can keep it on for days. Thats not consistent with a loose connection.

I had an outside 13amp socket that would work 1 day not the next, would also trip the supply, went on for weeks. The electrician had left a terminal screw loose.

 

[expleto]

Strangely it never trips the consumer unit, so logic would say that the live feed is being interrupted after it spurs off from the main line, it feels more like a switch problem as it seems to respond to events that are related to the switch opposed to some random timing of a loose screw further back, But I am kind of eliminating the switch as it was replaced and produced the same effect as the old one, but logically thats probably the most likley source of the problem. I think I will pull the switch off again and do some more tests...

...after more tests, it wasnt the switch, pulled cieling down and located connecting rose, turns out to be a loose connection

 

[Taylortwocities]

Glad you found the problem.

Why did you need to take the ceiling down?
The ceiling rose should have been mounted on the surface and available for inspection - as is the case with all screwed terminations.