Comcast Won't Work With DIR655 Router?

tried 2 routers, one brand new , both DIR655 from Dlink - an older router. Just got a Comcast internet connection. The internet is fine when connected to the laptop directly. The router can talk to the computer. but plugging the internet cable into the router, the router never quite finds it, ie the blue indicator light never indicates access from modem to the router. So cant get that extra protection from the router, or the convenience of it.

By the way I am doing all of this hardwired even though the router is wireless capable. I did a hard reset which I could log on and see worked of the router. This happens when it is not hooked to the computer. I did the thing of powercycling modem and router, no change. Do I need a newer router? Is there something weird about Comcast, these were fine w Cablevision. Comcast tech support was useless.