PA9020P powerline light remains red in all rooms
I recently bought two PA9020P adapters to replace two older, lower speed, models. I used one as my main adapter without problems. But wherever i try to use the second one, the powerline led remains red and it will not pair. I've tried all the rooms, garage as well, and tried to pair it with different adapters on my network without luck. I understand a red powerline led means poor signal strength but all the other adaptors, including its sibling, work well.
How can I test if there's something wrong with the specific adaptor? Or any other idea as to what might be the problem?