hi.

I was wondering what this circuit board is and whether I can buy a replacement anywhere. Its connected to a phone line to be used in an extension sockets but has stopped functioning. I’ve attached the files to the post.

Many thanks

 

What is on the other end of the cable?

 

What is on the other end of the cable?

I’m assuming it goes to the master telephone socket in the flat I’m in.

 

... no components ... so the problem is a poor connection someplace. Try spraying liberally with electronic contact cleaner. Also jiggle each wire where it fastens down ... they usually tend to come loose or break towards the end, where they get bent a lot. If you are careful, bend the copper spring contacts a little so that firm contact is restored.
... Try the contact cleaner first, a small brush might help. Maybe the copper contacts have oxidized due to humidity or other moisture.