Home phone wiring -- 50V DC at NID but no dial tone?

Factual Questions
1

Just got new land line service from AT&T. They told us the service should be active.

I put my multimeter on the different pairs at the NID, and sure enough the blue/blue-white pair has ~ 50V DC across them (nothing on the others). However, when I connect a known good phone, there is no dial tone, just a little crackling as the wires make contact, but then silence. Tried hooking up a different jack in the NID but same result. When I dial the number, the “caller” gets a ringing tone, but of course any phone connected doesn’t ring.

Can’t get hold of the phone company for service until Monday. Is it possible that I’m doing something wrong here? Is there a logical reason why I’d see the voltage but not get any dial tone?

2

Try swapping the wires. Tip (color) and ring (color w/ white stripe) have to have the correct polarity to work properly in many modern phones.

3

I tried both polarities already – same result.

4

In that case, it sounds like a telco issue. Sorry.

ETA: does the line voltage drop to about 10 VDC when the phone is taken offhook?

5

I had a similar problem with my house. It turned out that the wires and connectors had gotten dirty and corroded and did not transmit enough voltage for the phone to work sans static and poor volume. It measured 50V but the phone did not work for shit.
I took everything apart where the wires came into the house, cleaned the terminals and wires with steel wool, and life was good again.
Then I got the local phone company to install a modern box (no charge)