As part of troubleshooting connectivity issues, I replaced a personal Motorolla Modem with a new Xfinity modem. Installation was pretty easy and all services are working fine.
I can't run a speed test or do any other diagnostics because the old modem is still associated with the account; in fact, XFinity reports they can't detect a signal to my house. What do I do? (Besides making ANOTHER trip to the brick and mortar to fix problems with an old account for some MYSTERIOUS reason, Comcast keeps hanging around even though I deactivated it 3 1/2 years ago).
I *sort* of had the same issue, although it was over one day, not the three and a half years you are describing...
Just got a new modem yesterday, and went through registering it with a rep over the phone. Everything worked fine. This morning I went to My Account on the Xfinity page, and saw the message "We're having a problem reaching your equipment" or something along the lines of there being trouble, or no signal detected.
When I looked at my equipment, I saw my new modem, but I also saw the modem that I replaced, with a message "Issue detected"
Luckily, I was able to get a competant rep in chat, provided him with the old modem details, and he removed the modem completely from the account. As soon as he did that, I refreshed the page, the error message went away and changed to "Everything looks good", and the old modem was no longer listed.
I replaced my personal modem with a Comcast modem. Comcast does not recognize that, although my services are OK and if I engineer a modem reset through the Comcast website, the modem is reset. But I cannot run any diagnostics on my connection because Comcast thinks there is no signal to my home. A separate thread asking how to fix this problem yielded no resuts.
The robo "assistant" or "agent" is of no use. So what one must do to speak to a human being???