@zDavzBR To be able to use all 3 devices without conflicts, I would configure the 820N and 740N in manual AP mode using this guide. The IP address for the 820N set static - 192.168.X.254 and for 740N...

@bjlockie Try connecting your computer to the AP by cable. If the AP works fine you should be able to open its management interface. Then set your wireless SSID and password as per your requirements.

@soundshaper213 Yes, you have to be connected to the AP's wi-fi so these pings make sense. You can do it either through the router's diagnostics menu or the desktop's command prompt. I dug up an old...

@soundshaper213 There are two ways: Through the router itself (embedded diagnostic feature) - here's how. Using a computer open the command prompt and use the ping command as in this guide.

@soundshaper213 Here's the connection you have to make between the two devices since there's no dedicated AP mode in C3200. DHCP server of the AP device (second router) should be OFF. AP WAN port...

@seventeen Have you set a static wireless channel on the root router ? If you haven't done that, when the root router (if set to Auto) changes the channel the WR740N will loose its connection.