Hi, 

it started a year ago. 
One of my x20 started to go offline. The led blinked really light blue, it seemed that one unit got broken. However after that I unplug it from the wall socket and keep it for a minute it solved the problem for a period of time. 
This happened couple of times, it was annoying but I could live with it. 
This February started to not work properly, a simple restart did not help at all. 
 

That moment I went to the shop where I bought it. There is no official tp link service in our country. 
 

They told me that I need to return all the three units, so I went home, plugged it in and it worked till last week. 
This time the unit goes offline really fast, like in less than an hour and the led is off completely. No light blue, no other color at all. 
 

As per today, the unit is out of warranty. 
 

I would be curious if you experienced something similar, if you know some tips and tricks,or I can consider it as broken. 
 

Thank you!