I have a Motorola MG7550 modem/router that has never failed in 18 months. Suddenly, I am unable to connect to either of my wifi networks. I got on a Motorola Modem blog, logged into my modem site and found a series of T-3 errors in the event log. The blog stated that, "If you see the T3/T4 errors, you will need to call your Internet Service Provider."
A very determined and helpful Comcast agent tire to reoslve my issue but to no avail. Eventually she directed me to this forum.