Locked on a downstream channel and Connectivity State == "Access Denied"

Did you have it activated / provisioned for service ?

So are you saying that they told you that they couldn't activate it ?

Is it brand new out of the original packaging or second hand ? 

Is this a new service at this address or have you had service there before ?

I bought it off ebay, reported to be new, open box. I had service at the same address, I just eliminated tv  and phone. 

Comcast sent a technician out and he even stated he has seen many people buy this very same modem and have no problem getting it to work.  He tried a few times to get it to connect. He went outside and checked the connection coming into the house and removed some stuff that he said I didn't need and it still did not connect. 

You take a chance when you buy a modem on sites like E-bay. Many times they wind up being flagged as un-returned / stolen in Comcast's database, and they won't activate them for service. 

Ok, but if that were the case, why wouldn't Comcast say so? More importantly, why wouldn't Netgear know this and say so??? They both have the serial numbers for the modem. 

I'm afraid that I can't answer those questions authoritatively, sorry.. I am not an employee of either company.