Can you test powerline devices using your computer instead of Sky box?
What's the IP address obtained on computer and Sky box when testing seperately?

Hi,
I did connect my laptop to Device 2 (instead of the Sky box) and interestingly it gave the impression of an internet connection (i.e. the laptop showed a connection) but then it failed to open any web page - so effectively was not connected. I will try again and also capture the IP address as well as I failed to do that last time

If they have been working fine for 2 years and suddenly stopped, it is quite possibly a hardware failure. The capacitors used on older TP-Link homeplugs are notorious for dying after 1-2 years. I lost 4 x PA211s like that. Although in my case they died entirely, with no green lights at all.

1) Plug your laptop directly into your router (same port as currently used by homeplug) to rule out a router failure.

2) Replace/swap around ethernet cables to rule out a cable failure

3) Plug your laptop directly into both adaptors alternately and reset via the TP-Link Homeplug utility.

4) With your laptop connected to one adaptor, what does the TP-Link utility say, can it 'see' the other homeplug? Is the connection speed normal?

5) With your laptop connected to one adaptor, and the other connected to your router, can you ping your router?

Hi and thanks for the help and suggestions! I finally got to the bottom of it - well, it's fixed now anyway.

The router was faulty... worked okay with one ethernet cable but the second cable that I'd used for the TP Link Adapter had failed. I put a new router on and now all works fine again

Thanks again