go to the outside telephone box on the house and make sure the phone company lines are disconnected. If it's a plug, then unplug it. The vonage box has a plug for two phone devices. Plug a cord between it and a wall jack. Check the other phones. Dial the number from another phone, such as your cellphone. See if there are problems. If so, turn off the ringers on all phones except the one connected to the vonage box and one connected to a wall plug, see if it works then. If so, then you can turn on the next most needed ringer and try again. The ringers use up electrical power so too many phones on a line ringing can interfere with the service.