Uverse not working on both TVs

Since I received the new gateway UVerse is not working

If you haven't already, unplug all TV Receiver, including the DVR, and your U-verse WAP if you have one.  Unplug your recently replaced Gateway, too.

Then plug in the Gateway and wait for all the lights to come on

Then plug in the DVR and let it boot up, make sure it works.

Then plug in the WAP and let its lights come on

Then plug in the rest of the receivers one at a time.

While you're doing all that waiting for stuff to boot up, make sure that any cables that are supposed to be connecting things (like the cable from the DVR to the Gateway) are properly connected.