why has the lights stoped working in some rooms?

Midlands Sparky undoubtedly has more experience than Peccavi but in this case his logic fails him.

A disconnected incoming Live or Neutral would cause that particular light not to operate so there's a 50% chance he's right in his assertion, "it will be at the last one that is working."

Lord Finchley tried to mend the Electric Light
Himself. It struck him dead: And serve him right!
It is the business of the wealthy man
To give employment to the artisian.

Peccavi's friend
January 2009

You need to check the connections at the last light fitting that is actually working. The fault will not be at the light fittings that arent working it will be at the last one that is working. Be aware though that although your light switches may be turned off there will probably be a permenant live suppy at the fittings so make sure you turn off the circuit breaker or remove the fuse for this circuit before you go hunting for the loose connection.

Midlands Sparky
January 2009

The wires that take power to the lights usually move from room to room like a daisy chain - saves on cable costs. If either Live or Neutral become disconnected at one ceiling point all the other lights that come after this will stop working.

Carefully examine the ceiling roses and look for a detached wire - In the UK Red or Black in colour for Live and Neutral or even Brown/Blue if you have the new Euro wiring.

The broken connection might even be at a working light i.e. the incoming connections properly attached but one of the outgoing not.

Take care...

Peccavi
January 2009