Intermittent Internet connectivity

Over the past few weeks, I've been dealing with my Internet service not working for periods of 30 seconds to a few minutes. It happens randomly and several times a day. I tightened all of my coax cable connections, reset the modem, and called customer service multiple times.

Last week, Comcast was going to send a technician out to diagnose the issue. But then I got an automated call saying that Comcast identified the issue, resolved it, and asked me if I wanted to keep my technician appointment. As the issue seemed to improve and believing the problem was fixed on Comcast's end, I decided to cancel the technician appointment.

The intermittency issue stopped for several days, but it started up again two days ago. A call to customer service resulted in a test that indicated a poor connection, so I have another technician appointment tomorrow. But I just got a call this morning indicating that Comcast may have resolved the issue.

Is there any way to find out exactly what Comcast has identified and what it did to supposedly fix the problem? Can Comcast analyze the logs on my modem to figure things out? What's so frustrating about the intermittency issue is that whenever I call customer service, their checks indicate that everything is fine. Any advice on how to connect with the advanced technical service team would be appreciated, because explaining everything again and again with the regular customer service line is so frustrating.