Device light won't come on

My EX3700 is about a year old. It has been successfully connected to a Linksys router, but after getting some tech support on the router, the device light on the extender was out. I though I'd have to reset the extender, so I tried that multiple times. The setup goes as expeccted until I get to the set up pane that says "we are applying your settings. This may take a moment." After a minute or so, the window poofs shut, and there is no further communication. The device light is never on. At. All. The router, power, and WPS indicators are all green. At least 3 times today, I have started again at the factory reset, worked through setting up the passwords, etc., but the window always closes before the message that should appear confirming the extender is connected to the WiFi network. 

Thanks, Pat