Can't connect to wifi network - T-3 errors

[BruceCharles]

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. 

[EG]

Start here;

https://forums.xfinity.com/t5/Your-Home-Network/Internet-Troubleshooting-Tips/m-p/3310447#M316652