Chainging the bulb causes problems

[knhobson]

I had to replace a bulb upstairs.
The lights began to flicker and I decided to check the wiring.

As I started to remove the rose the lights went out.

Now some of the lights upstairs do not work, but others do.

I can't see that any wires have become disloged, and no fuse has tripped in the main fuse box.

Any ideas?

 

[dingbat]

As I started to remove the rose the lights went out

Jeez, you did this live? You clearly put a low value on your life.

Whether or not you can see it, at least one termination has come loose.

 

[kevnurse]

I get the impression that knhobson believes that if the switch at the wall is off that there's no electricity in the rose.

Mr knhobson, be advised that ceiling roses are primarily junction boxes in a circuit of live wires supplying all the lights on that floor level. Accordingly, you must either trip the mcb or remove the fuse in your consumer unit, for that lighting circuit, before you open any ceiling rose. If you have any doubt about which one to deal with, do the job in daylight and switch off the main switch in the consumer unit.

I agree with dingbat that the most likely cause of your problem is a loose screw or a badly fitted wire in one of the terminals in the rose you opened.