I've severed your post from the original thread as you are not the original poster and you need to have your own issues addressed separately.
That said, what exactly is the problem? You have no signal at all? Post your modem signal stats here as instructed by this thread.
Even if the problem is on Comcast's end, the repairs would start by sending a premise tech to your home. If the problem is related to outside wiring, you won't be charged for the visit.