For no visible reason, at least around here, my high-speed Internet connection just began working again. This is the way it always is with Comcast, at least in my experience. They say, "The problem's on your end, we'll have to send a man out," and they schedule one for a few days in the future. Then, before he gets here, they fix the problem on their end.
However, just in case, I'm going to wait 24 hours before I cancel my Tuesday afternoon service appointment.