Orbi RBK53 suddenly stopped working

I've had a Netgear Orbi RBK53 set up and working very well for the past several months. Yesterday, our internet suddenly stopped working. I finally determined that it was an issue with our Orbi router, as if I connect directly to the router provided by our ISP, the internet works fine (though only in parts of the house close enough to reach it, of course).

I tried setting up the Orbi system from scratch, after doing a reboot, but I'm unable to complete that successfully. Most of the time, that fails after trying to connect to the ORBI10 network, with the message, "Unable to join the network ORBI10". One time I was able to get past that, even set up the netwrok name and password, but the final application of configuration details failed and I was unable to connect to the new network. At this very moment, the router is pulsing white. 

Any ideas what might be wrong, or how to fix it?

Thanks,

Reuven Weiser