CM1000 + nighthawk 65 loosing connectivity issue

i Just bought the cm1000 modum and Nighthawk 65 wifi unit. never had an issue before i got them.. ( internet provider is Comcast ) so my issue is that all is up and running smooth then every day and a half I can not access the internet though all my devices say connect and show a strong signal. also my main computer which is off a cat 5 from the router also can not access the internet. so i re-boot  to regain accesss. this what is causing this i have a home securet that requiers the internet and when away i can rest things. Plus after 2 wweek it is starting to be a bit of a pain. thanks in advance for any help i can get.