Frank, i work for Comcast. Sorry we are not in your nek of the woods.It is less common to have a bad modem ,than poor forward signal or an upstream signal issue.some times interfering signals get in the upstream[from poor cableing in other homes or damage somewhere in the local area]if you look at Best buys web page or look around you should be able to find a modem if indeed that is whats wrong[usually something else though] good luck,and contact me if ican help.