I bought goCoax's WF-803M but it isn't seeing or pairing up with Summit Broadband's iPhotonix. What can I do to get them to work together?

That's a frustrating situation! I had a similar issue with my own MoCA setup. First, I'd double-check that both the goCoax adapter and the iPhotonix device are on the same MoCA channel. Sometimes they default to different ones. Also, make sure MoCA is enabled on the iPhotonix. If those are good, try resetting both devices. Finally, sometimes signal strength can cause issues; are you using any splitters, and are they MoCA compliant? It's a bit like troubleshooting why your grandmas' computer can't run Cookie Clicker , sometimes it's something really simple, but you just have to check all the connections first.