XAV5421 & XAV5201 powerline devices won't give an IP on electrical outlets in living room only

So the 169 address isn't really an address at all coming from the router.  That's what devices are supposed to 'auto-assign' themselves if they don't find a dhcp server.  Stupid, I know.  I've never found a use for this.  It was a lot easier to diagnose things when you simply didn't get an address.

So you're basically not getting any IP in that living room.  There's a couple of things to check.  You mentioned that the 5421 gives you an IP address (proper 192 one coming from your router) in other outlets, but just not in the living room.  Do the lights on the 5421 indicate it is getting a powerline connection to the other powerlines?  If so, how strong is it?

If that is all okay, next thing to check will be the ethernet cable that goes from the 5421 to the computer and the link lights on both the computer and the 5421.  Do both the computer and the 5421 indicate a link?  If not, try a different cable and see if that works.

Report back what you find and we'll go from there.