System was working fine until I had to rearrange it for new internet; now, even with the powerline devices in the same room, the powerline lights never come on except briefly during power-up or reset. I have tried plugging the devices into different power outlets, tried resetting multiple times, no luck. Using the online utility instead has been useless as it does not recognise that the extenders exist, however the tether app has occasionally registered that they are there so I know they aren't completely defunct. 

It's a TL-PA411, AV600 wifi extender.