R6300 not detecting Ethernet connection

Purchased a second hand R6300 in the hopes of improving connection speeds over an old Belking Wireless G router distributing data from Cable modem.  Original setup is Cisco cable modem - belkin router - wired and wireless connections.  OK but not flash. 

Connected R6300 to Belkin via ethernet cable, and was able to configure netgear wireless 2.4 and 5ghz connections, and use them to connect through ethernet Belkin connection.

Set Netgear internet settings to match Belkin settings (gateway, fixed ip address, dns servers).  Unplugged Belkin from cable modem, plugged Netgear into cable modem, all wonderful.  Connection speeds wired and wireless all boosted.  BUT - still a dead spot in one part of house.  Thought "I'll set up Belkin as a bridge / extender, and all will be wonderful".  This is where it turns to custard.

Updated Belkin to activate "Wireless Bridging".  Looked into Netgear settings and found Advanced wireless setup and turned on access point mode.  Lost connectivity to setup, wireless and wired networks.  Logged into Belkin and turned off wireless bridging mode, and was able to restore Belkin wired and wireless connectivity.

Performed a Factory Reset on the Netgear R6300. Now can't connect to ethernet / internet from R6300.  Home page status has internet "not connected", other devices connecting to Belkin ethernet ports are ok.  Executing the "Advanced Setup Wizard", I select my country (New Zealand), then it does a "Detecting the Internet Connection" for a few seconds, then comes back with "Problem Detecting the Internet Connection - IP Address".  Selecting any of the options and then entering the device's mac address, still get the "Problem detecting the internet connection".

So now, I have an extremely glamorous paperweight, it seems.

Is there some setting that needs adjustment to get it to recognise the ethernet connection?