I've had my unit for over 2 years now and had very few issues that couldn't be resolved with unplugging it and plugging it back in.

Now suddenly the devices do not want to pair with one another at all.

The adapter has the power and internet lights on, but not the powerline connection light.

The extender has the power light and wifi light on some of the time, the wifi light flashes occasionally, and not the powerline light at all, as with the adapter.

I have tried:

Unplugging my router for 15 minutes (no other issues with wifi on other devices).

Unplugging both devices for a couple minutes.

Hard resetting the device.

Trying to pair the device.

Its network is not even showing up in my wifi options, so I cannot check on it through the app that I downloaded when I first got the device since they have to be on the same wifi connection. I don't believe this particular model is compatible with the Tether app either. 

Any ideas on potential issues or solutions would be helpful. I lost the instruction manual for this unit a while ago so I'm working off whatever I can find online to try to resolve the problem.