C3600 Internet constant blinking upon install

I purchased a c3600 yesterday and upon install the internet light never stopped blinking. ISP is Cox and they couldn't 'see' the router cause it never came online. I exchanged it today and still same problem...I reached out to Netgear CS and they couldn't provide any assistance and still no luck with Cox. Anyone had this happen? All Cox reps I spoke to said they've never had an issue with this model. Thanks in advance