Is quite an interesting thing i'm in crew accommodation at the moment. And when when we moved in there was one of the lights kept flickering in the hallway. I fixed it by replacing the lamp holder because this existing lamp holder was arcing internally. And it's quite unusual because it's a safety lamp holder and i never actually seen one of these in the flesh.

So far so well what better thing to do than take it. Apart. Let's get down closer to this so. Here's the idea in the uk.

We have what are called bainit cap lamp holders. Which are the two pins out the side and then the two contacts the end and this is not electrically connected to anything some sometimes it's grounded. But usually it's just live neutral. Whichever priority you put it in with the normal socket.

You've got the two pins at the back. And if you were to poke your finger into it you could get an electric shock. However with this socket when you put it in it hits an interlock and it the pins aren't live until you actually twist the lamp. But this is making crunching noises.

This is not twisting. I think that may be the problem the back of it has already suffered plastic fatigue and has snapped off let's get a screwdriver and pry this apart and see how it comes apart. I can see little tangs here. Oh.

That's not so bad. This is very brittle. I think this lamp holder is old enough to belong to the era of uh tungsten lamps that are very hot okay right there's where it was arcing so the connections in the back uh just come down to these two pins that then rub onto these contacts and i'm going to guess. I'm going to guess that when i put this in and rotate.

Oh. It's scrunching. It's yeah. I don't think that was supposed to happen uh.

Let's just keep exploring it then oh. This is absolutely baked let's keep going down. I shall poke the guts out oh this is crumbly to bits. It's just absolutely wrecked.

Where is the other spring. Oh there's other spring. I think now it's actually stayed in place. Oh.

The plastic's broken that's why around there so how does this mechanism here is the shutter that rotates is it just rotating well now i've removed the crunchy bits let me see if i can reassemble this so. When the lamps put in when the lamp's put in it is rotating that plate inside okay um and when it rotates that plate inside. I'm guessing that these contacts that come down onto these pins probably have little uh. They do have little spring loaded contacts underneath not quite sure they were supposed to go in oh.

They're supposed to go in like that and that in rotating um all right. I'm just gonna have to have another go at this so the actual the contact pins stay put. But this rotates and i'm guessing then that this springy contact does just rotate onto these pins. It must move and slide on them all right tell you what i'm going to try and assemble this it could take a while to work out this puzzle.

But i shall try and assemble it and see if i can work out what's going on here one moment. Please well that didn't take too long. I've worked out how it works as you twist the lamp. It actually slides those contacts backwards and forwards.

I thought they were going to rotate. But they actually slide sideways. So these are sliding contacts on the top here and it just sits in these tangs and when they slide. They move backwards and forwards this spring loaded contact and to make contact with uh.

The actual pin in the back of the actual socket. The one that the lamp is making connection to so that's interesting an interesting mechanism different different different to what i was expecting this one is definitely showing the signs of heat. There's a certain thing that you know led lamps may kind of bake themselves. I mean we've featured this many times this channel.

But uh technically speaking. Now the lamp holders are going to last a lot longer because they're not subject to the same thermal fatigue. They used to be so uh very interesting actually i'm glad that failed now and so we could take it apart and see how it worked that was quite fun.