Hi,
If you suspect the powerline adapters are failing or not working correctly, then there are a few ways to test these.
First, make sure each adapter is in a working socket. If the power light fails to illuminate when the socket is turned on, then it's time to replace them.
Make sure each adapter is direct into a wall socket. If connected via an extension block or surge protector socket, their performance may be reduced.
If the adapters are failing to 'pair', plug the adapters side by side into a double wall socket to test.
Press and hold the pair button for 10 seconds on each adapter to clear the previous pairing.
Re-pair the adapters ans see if this is successful. If it is, you can place the adapters back in their original position. If they fail to pair, try alternative sockets to rule out any internal wiring issues.
You can also check out our Powerline Adapter Troubleshooting Article.
Thanks
Karl.