I have Belkin N150 Rouer.
f the modem light keeps blinking, it means that the router hasn't been configured yet. Also, rarely, it can be an issue with WAN port/modem port on the router or the ethernet cable connecting the modem to router or finally, modem may not be working as its not applicable in this case(as you said).
1.Connect comp.--(gray port) router (yellow port)--modem
2.On the computer, open the router page by typing 192.168.2.1 in the address bar of browser
NOTE : IF YOUR INTERNET SERVICE PROVIDER IS CABLE FOLLOW THE BELOW STEPS
3.Under Internet WAN , SELECT the connection type as Dynamic.->NEXT
4.On the far left column, click on "MAC address" under Internet WAN.
5.Click on clone and apply changes and finally check Internet status
6.If internet status > Not connected, we need to do a network power cycle
7.For this, unplug the power from router, then from modem, then unplug the coaxial cable from cable modem.
8. Wait for 60 sec, then connect the coaxial cable, then connect power to modem, wait for lights on modem to get steady, then finally, plug in the power to router.
Now, you may see proper lights lit on the router.
All my best wishes for a fast internet service through the router.
FOR PPPOE OR DSL CONNECTIONS
1.Under Internet WAN , SELECT the connection type as PPPOE ->NEXT
2.ENTER THE USERNAME & PASSWORD PROVIDED BY YOUR IN INTERNET SERVICE PROVIDER
3.CLICK ON APPLY CHANGES
For any advanced help, revert asap!
Thanks and regards,
MILAN