Yesterday I was installing some downlights in my living room which I have
done twice in the past in other areas of the flat. After checking the
wiring was correctly done I plugged the 5amp fuse back into the fusebox
where it blew.

I was baffled especially after rechecking everything again and then to
rewire the fuse. After rewiring the fuse I plugged it back into the
fusebox where the lights now all worked after switching them on. I
couldn't understand at the time why the fuse blew.

Later in the evening I went to the bedroom which is on the otherside of
the flat and found that the downlights didn't work in there. It seems as
if the problem with the fuse blowing may have come from the bedroom which
I don't understand. The two other bedrooms, kitchen, bathroom, hall and
living room have lighting except for the third bedroom which had been
working the previous day.

Today I have changed the lighting switch and connected a normal 60W mains
powered bulb which cut out the use of the transformer where the light
still won't work. Using a pocket mains tester (screwdriver type that
detects current) it seems as if there is no power going to the switch nor
to the lights.

Prior to this happening the 5amp fuse did buzz a bit when turning on the
lights in that bedroom. The downlights fitted in there where bought from
B&Q 4yrs ago which consisted 3lights and one transformer. There was a
dimmer connected as well.

I'm not exactly sure if the problem lies with the ceiling rose in that
bedroom or somewhere else. Would anybody have any advice before I call
out a sparky? I can see it'll probably be expensive as i'll have to cut
through the plasterboard to get to the ceiling rose.

TIA

P