Dip headlight not working

Here's my problem. 110 200tdi, 1992 defender.
Off side dip headlamp is not working.
Both main beam lights are working. And side lights.

I have tried the fuse and i swapped the left and right fuses around and the fuse is ok. There were sparks when I put the fuse in the left lamp slot.
I looked at the wire on the lamp itself. There's a red one that plugs into a red one that goes to the side lamp, that's working ok. I unplugged it and plugged it back.

What could be the problem you all think?

bulb?

As Ste says, bulb.

Although they're the same bulb there is two separate filaments so one can continue to work whilst the other is fecked.

Ah! Thanks for the info.

That's good to know, will get a new bulb tomorrow.

Thanks for the help. Yes simple as the bulb was blown,

In other news, I took it apart and changed the bulb. There's been an upgrade (or change) of some sort and there are led parking lights (maybe) just loose behind the case, they work but can't be seen from the outside.