Light fixture fitted - only 1 of 3 bulbs light up?!

[ShortyK]

Hey folks, changed a light fixture for my parents today, it was a working one from the dining room which was going to be fitted in the lounge.
I fitted it, but stupidly the light was one of those ones were you can barely see the colour as they're almost transparent plastic casing, anyhow I figured it out (after getting it wrong twice) but afterwards, since turning it on only one bulb works.
Strangely, if I change that bulb to another socket, it works, but it's only ever one working.
We tried different bulbs but no success, just one bulb works.

Things to note
It's on a dimmer switch - but the light does not respond to dimming - I need to double check their bulbs as the previous room was also dimmer switch.

I'll try different bulbs tomorrow, but also thinking a loose live wire?

The switched one is the wire I checked and refitted, but didn't check the others.

Any help appreciated

 

[Wayners]

Did you swap bulbs from something like halogen to led?
Is the dimmer compatible with led bulbs.
Got a picture?
Has the light got a led driver?
Strange problem to have

 

[ShortyK]

It's very strange, because the bulbs that were in there, were the ones that were working beforehand. I'm not sure whether they dimmed or not, the only difference would be the dimmer switch is different to the dimmer switch in lounge I guess but I'll bring dimmable bulbs tomorrow to rule that out.
That's the pic I've got before it was changed. That's the electricians wiring and tape.
I've replaced it all with wagos.

 

[terryplumb]

Do you mean one bulb works in all positions ?
If so connect the permanent live to the switched live at the switch position and see if all lights work. If they do the dimmer is the issue.

 

[ShortyK]

Do you mean one bulb works in all positions ?
If so connect the permanent live to the switched live at the switch position and see if all lights work. If they do the dimmer is the issue.

Yeah it works in all positions but just the one bulb, will try your suggestion tomorrow thank you!

 

[333rocky333]

Bit concerned about the transparent wires you mention you got wrong twice?, was there 1 or 2 to each lampholder, these obviously need to be connected right,

 

[ShortyK]

Bit concerned about the transparent wires you mention you got wrong twice?, was there 1 or 2 to each lampholder, these obviously need to be connected right,

3 wires from the lamp and one earth from the metal part.