Mystery electrical problem

JuzaMum

Xmas eve I turned on a light downstairs and it didn't work. I think it flashed as I turned it off again. Half the lights on the ground floor (were the room is) now don't work. I checked the consumer unit and nothing had tripped so nothing to reset. Before I call an electrician out does anyone have any bright ideas? Thanks

47Revisited

Circuit will be on a radial. Wire's come loose.

47Revisited

Isolate the lighting circuit by turning the MCB off at the consumer unit. Then check the ceiling rose/light fitting for a wire that  has come out of the terminal. Maybe switch as well depending how it's wired. Ideally done not at night.!

JuzaMum

47Revisited said:

Isolate the lighting circuit by turning the MCB off at the consumer unit. Then check the ceiling rose/light fitting for a wire that  has come out of the terminal. Maybe switch as well depending how it's wired. Ideally done not at night.!

I'll give that a try in the daylight

FaceHead

I'd start with the switch and then move onto the ceiling rose. And if there is nothing obvious, get a £10 multimeter so you can test things and methodically find the fault. 

The switch is the moving part that gets bashed about, so it's the most likely place something will slip out after years of working fine. Also no ladder required. 

(Of course it would have to be wired in the right way for a problem at the switch to explain this behavior)

FaceHead

I'd start with the switch and then move onto the ceiling rose. And if there is nothing obvious, get a £10 multimeter so you can test things and methodically find the fault. 

The switch is the moving part that gets bashed about, so it's the most likely place something will slip out after years of working fine. Also no ladder required. 

(Of course it would have to be wired in the right way for a problem at the switch to explain this behavior)

JuzaMum

Checked the switch and changed the ceiling rose but still in the dark!

GDB2222

What makes you think that the fault is in that light?

TadleyBaggie

If several lights aren't working it strongly suggests a fault with the wiring further back towards the CU. Modern lighting circuits will have a 3 red or brown wires, these will be the live in, live out and live to switch. There will also be three black or blue connections, two of which will be the neutral in and out. The other black/blue will be the switched live.

if the live or neutral has become disconnected at a ceiling connection, all the lights beyond that will not work. If you don't know the route of the wiring (and why would you) it's a case of checking each ceiling point in turn. 

If you have a multimeter you could check at a light that isn't working what the voltage is between live and earth. If you see around 240V then that would suggest the fault is on the neutral side, if you see 0V then the live side is looking like the culprit.

Section62

JuzaMum said:

Checked the switch and changed the ceiling rose but still in the dark!

Is there something special about the affected lights - such a them all being in an extension or something?

If not, call an electrician.  You'll get lots of tips how to fix it yourself from this forum, but unless you have quite a bit of knowledge and experience already then you will be very lucky to find the fault yourself, and in the meantime could be placing yourself in considerable danger.

Be particularly wary of 'advice' about how things should be.  There are certain standards that people are supposed to work to, but there is no guarantee that whoever did work on your house did the job properly and followed the standards.  Assume all wires are dangerous, but don't assume anything else.

JuzaMum

Thanks all. I have an electrician coming tomorrow as I don't have a clue!