The previous owner was anything but computer-literate! There was no cable or other kind of connections in the house. One phone line, kitchen and one bedroom. The house is 68 years old; the wiring in the old jacks is 4 wires, but I can't even tell the color of them now. But, Dennis, you may be right--it may be a defective wire; I can't follow it anywhere. We may have to give up on a phone in the livingroom for now--we installed the wireless jacks, but the interference from the other electronics in the house make them pretty much useless. If you have any other ideas, let me know. Thanks.