Intermittent Connection ... Comcast claims I need a re-wire

For the last month, our internet connection is horrible. We get dropped from the internet every 3-5 minutes for 5-6 seconds at a time. The first tech came out 3 weeks ago and said there was noise on our line and we would need a new pre-wire. Three weeks later, the tech comes out for the pre-wire but says we don't need one, that it was just loose wires outside. Wrong! Yet another tech is coming out in a couple days to try and work their magic and figure out what is going on.

We have 2 computers that go through a modem. We have tried completely disconnecting the modem and hooking the cable modem directly to each computer but encounter the exact same problem. We have changed out the wires between the modem and the router, no change. We know it's not the computers because both computers have the exact same problem. We have had this setup for over a year and did not have any problem until about a month ago.

Any ideas since the rocket scientist techs they keep sending me don't seem to have any clue?