Wifi Extender EX3700 intermittent connection

[lpeecee]

I bought this extender several months ago.  It worked fine at first but now if I try to connect to it, it cycles through displaying: netgear setup genie; or 'unable to join network' message; or 'the wifi network could not be joined' message; or the ssid doesn't show up in available networks; or it connects to the network but then tells me there's no internet connection. And then it will suddenly work perfectly again for a while without me doing anything, and then back to the problems above. 

Meanwhile the main router works fine as does my other extender which I added to the system when the Ex3700 started giving me this trouble.

I have tried resetting my main router and factory resetting the netgear extender and this hasn't sorted the problem.
When it has these issues the router link led light is usually off.  When it is working fine the router light is green so the position of the extender doesn't seem like it is the cause of the problems.
At first when I brought it back into the room with the main router that was all it needed to get back on line but now sometimes I even get these issues when it is the same room as the main router and there seems to be nothing I can do to fix it so I just put it back upstairs in frustration and eventually it just rights itself and works perfectly.

[plemans]

Are the 2 extenders using the same ssid? Have you tried seperating them out? 

How far from the router is the extender? 

that router link light is kind of key. If its not on, the extender isn't connected to the router. it could be channel interference, it could be distance, it could be objects in the way. Have you tried moving the extender around to different areas? Many times things within the walls can block signal so moving a few feet closer/further away or even laterally can make a difference.

have you tried changing wifi channels? 

Is the extender setup in fastlane mode or standard extender mode?

If you log into the extender, it should show you the link rate back to the router for both 2.4ghz and 5ghz, what do you get?

What router are you using?