Hello everybody, 

One month ago I purchased the TP-LINK DECO M4 Wi-Fi Mesh (3-pack) to amplify the WiFi signal in a 3-storey house with dead spots. After the 1st day the decos started disconnecting and I couldn't keep a stable connection, not even for an hour.

To cut a long story short, I kept trying to get them to connect for weeks by creating the network from scratch through the app but they still kept disconnecting. Eventually, I switched the main deco on the ground floor (the one connected to the router) with the one that was on the 2nd floor. After that, the decos started working properly without any disconnections to this day which led me to believe that the previous main deco was defective. 

Here's the thing though. Right now, the main deco on the ground floor prefers to connect to the deco on the 3d floor which is pretty far away instead of connecting to the deco on the 2nd floor (the defective one) so that it could relay the signal to the 3d one. So basically, now both satellite decos are connected to the main one without optimizing the distance between them.  Finally I should also mention that the defective deco used to make a weird sound as a main deco and it could easily be heard if someone got close, and it used to overheat quite often too. Now as a satellite deco(the defective one) , it barely makes any noise but I really can't tell if it's working 100% properly or if it's just barely managing to work. 

Summing up, what should I do with the defective deco? Should I overlook the fact that it wouldn't work whatsoever as a main deco no matter how hard I tried? Should I overlook the fact that it doesn't connect to the 3d deco and it only connects to the main one ? Should I also overlook the noise and the overheating that it used to do before? Or should I return it anyway so I can get a new one? Sorry for the long text, but I really need an answer with this one. Any help is really appreciated. Thank you very much in advance.