Hi. I connected up a new halogen lamp to a six-way socket array. A minute or
so later there was a phut, then, after a few seconds, the halogen lamp went
out. I tried to switch off the mains socket, but it seems to be stuck. So I
just pulled out the six-way socket array, and plugged it in somewhere else.
It's ok.

(The fuse cupboard looks normal. I don't think anything has tripped.)

So, what could have happened to the frozen switch? How can I fix it?

Thanks.