UK Took down light to fix pendant light. Wires are live but nothing works, not even the old light now

[brianmoooore]

The joint box is usually on the landing, just at the top of the stairs…. But as above, you’ll need to lift carpets and boards to find it.

It will be a square or rectangle plastic box with all the grey twin and earth cables running into it.

I know the sort of box you mean, but I associate these with earlier wiring, often VR. I think I've even seen them used with lead sheathed, and some with cable clamps as well.
I reckon this is more likely to be a round 4 terminal box with a screw on lid and used one per light.

 

[littlespark]

Never seen the round joint boxes being used in this way. Just as addons later on, or maybe a single room where running more than one cable would be a problem.

From my experience, and this could be a location thing, but lighting circuits have either been central joint box, loop in at light, or nowadays, loop in at switch.

This is only for t&e and 3c&e cables.

Older properties may have been done in steel conduit and singles.

 

[brianmoooore]

Must be regional differences - we live and work at opposite ends of the country. The vast majority of rewires I did back in the day were from a mixture of VR, polypropylene and two core PVC to PVC T&E, and nearly all were originally wired with one four terminal j/box to each light.
Never seen conduit in a domestic property to this day.

 

[mainline]

Round junction boxes are very common in the UK for lighting installations