Customers often buy surge protection for the power connector on their computers but leave the modem line unprotected and plugged into their phone service. Most damage from surges that we see are due to lightning strikes that come into the computer by the phone line. A modem that has been damaged by a surge will often report no dial tone or fail to initialize. It might work when you go to bed and fail the next morning when you attempt to use it. Unable to Dial This indicates either an incorrectly install phone modem, a failed modem, or a phone line problem.
Most modems have a second plug that allows the installation of a phone.
Plug a know good working phone into the modem while the modem is connected to your line and see if you hear dial tone and if so if you can call. If not then disconnect the line from your modem and connect it directly to the phone. If this fails then you have a phone line problem. If the line is good, use terminal or Hyperterm to dial into our service. If it fails then you have a modem problem, if it works, then you mostly have a problem with how your Internet dialer software is configured.