I have a new Netgear RAX10, and an older Tp Link AC1750 router.

I want to use one of these as wifi router for the Century Link modem that is installed in my house. Ive been on and off with providers and thought Id check in here because nothing is working.

Wifi from both routers is strong

Internet is flowing to the modem, but both routers are not receiving signal from modem. Swapped cables multiple times.

I can't remove the modem from the wall to see model number.

Complication: no accessible device with ethernet jack, but there is a desktop in the basement.

Accessing router interface through phone is unreliable.