All assembled OpenSprinklers have been tested and should be able to connect. It’s possible that its DHCP doesn’t work with every router. You can try to disable DHCP and set a static IP. You can do so by entering setup options (press and hold button B3 while starting the controller), navigate to the ‘Use DHCP’ option, turn it off, then set the four fields of the IP address (make sure it’s unique and compatible with your router’s settings), and also the four fields of the router’s IP. Then press and hold B3 to save the options. See if this makes it work.