Activate new x1 box (replacing an existing, working x1 box)

I recently had a new "upgraded" x1 box shipped to me (in response to an onscreen message that I needed to upgrade to the newest box to received certain channels).  The old box (about 7 years old) was working fine.  I only have a single box in the house.

Connected the new box and it doesn't work.  I just get a 'no signal detected" message on the TV.  No activation message (or anything else appears).  Wasted hours trying to "reset" the box via the xFinity website; tried manually unplugging and restarting the new box, but nothing works.  Wasted more time searching for solutions on the xfinity website and forums but still no lock.  Either I received a defective box or there is a simply activation step that I need to do, but can't find the info. anywhere.   This is a situation where a simpe 1-800 support phone number would likely resolve the issue in a few minutes, but xFinity/Comcast doesn't offer that anymore.

For now, I've reconnected my old x1 box and all is working fine.  Before I was more time driving to an xFinity store to return the piece of junk they just shipped me, does anyone out there have a suggestion?

Thanks.