Airport Time Capsule 2TB A1470 - WAN port not responding

I am having trouble setting up a used Time Capsule (A1470) as a standalone Wireless Router. I can’t seem to get the WAN port to respond when I connect it to my cable modem. When I daisy chain the TC to my existing Applie Airport Extreme (using the LAN port), I can use the Time Capsule fine -But not as its own wireless router and storage solution.

I brought it to apple who couldn’t help (out of warranty), but I am wondering if anyone has experience either replacing the WAN port or the entire logic board that it is attached to.

Thanks!