Power goes off all over the house for switching on light or using a random plug

[madmarkuk]

Hi all,
Last night, I went upstairs to bed, put the main bedroom light on, then switched on the bedside lamp. Once I turned on the lamp the power went off (lights sockets and all), but this was after the main light had been on for a minute or so (this is an important fact, as you will see). I unplugged the lamp, and turned the power back on. BUT when I turned the main bedroom light back on, the power went off, and does so every time I try to turn it back on now. All power, all over the house goes off. The same happened if I plugged in my xbox last night in a socket downstairs (but this morning when I teste xbox, poewer was fine. When I tested light upstairs, power went bye bye).

I have four main fuses in my electrical box downstairs, one each for shower, cooker, lights and sockets. Does anyone have any idea what the problem could be? If so, how do I fix it, or how much will it cost to fix it?

Thanks in advance

[buildersmate]

Have you got an RCD (residual current device) in your consumer unit? These things work by detecting earthing faults in the circuits they are connected to. You reset them by flicking a switch - which you would have had to have done to get the power back last night. If you have, there is an earthing fault in the lighting circuit upstairs.
It is not usual for them to be connected into the lighting circuits (just the power circuits). Its not a problem if they are, though.
If the above is the correct diagnosis, it is safe to continue to use the rest of the circuits, but you will need an electrician to find the fault in the upstairs lighting circuit.

[woodchopper]

Something similar happened in our house a couple of years ago - had to get a sparky in and he traced it to a neutral going to earth somwhere - didn't matter what we turned on - threw the trip every time.