Are you removing all telephones when you test?

I would seperate all telephones from all the jacks. I would then open a jack and use my voltmeter across the tip and ring, usually the green red and measure the co battery. It should -48 to -52 volts dc. Keeping your test leads across the tip ring set your meter to AC and have someone call into the telephone number assigned to the jack. You should see the digital numbers or bars rising or falling. I used to carry a cheap analog meter because it had a needle. When set to AC on incoming ring the needle would move back and forth along with the ring voltage. You should see it peak at 95 to 102 AC.


Forty six years and still fascinated with Telecommunications!