How can a junction box go kaput?
Why do you want to replace a junction box with a transformer?
Why do you want to install a transformer when you are using LED lights?
- It states it's a 240v transformer, its not a junction box. You need a transformer for LED lights, right?
So I disconnected the white transformer ... now only one light works.
1 out of 10, or 1 out of the 5 which were working?
1 of the 5 which were working.
Indeed.
And the rats nests of cables, junction boxes and transformers isn't helping.
Take it all out and start from scratch.
No, I will replace rather than paying someone £100 to do it in ten minutes.
So I'm guessing the transformer powers four of the lights,
You must not do electrical work on the basis of guessing.
I worked it out, no longer a guess.
The black junction box powers five (could this have its own in-built transformer?),
No.
All the old halogens were the same were they, all 12V?
Yes
The bathroom is downstairs, only one half is accessible though the floorboards upstairs as the other half is under the roof.
You really do need to get access to that.
Impossible.
Given the quality of the work we
can see, there might be potential danger lurking where we can't.
And I can guarantee that the numpty who installed them will not have put properly sealed enclosures over them, so warm moist air from the bathroom will be getting into the roof space, where it might well condense and cause the roof timbers to rot.