Phone Line Died

I have two phone lines in the house. The first is for the home phone which has three phones connected and is working fine.
The problem is the separate, second line. This is used only for the fax machine.
About six weeks ago the fax machine lost the dial tone. I called AT&T who came out and tested the outside lines and they were fine. But to come inside and check around they charge $110. I'm going to try a few things myself before going that route.
For instance, I have swapped out the fax machine with another to see if it was the fax. Nope. Same result.
I went to Home Depot yesterday and bought a new jack and replaced that with the old one. Still, no dial tone.
Any suggestions on what else I can try before calling in Ma Bell? Thank you.

 

What changed 6 weeks ago? New jacks? Did you move the fax from one location to another and plug it into a different jack? Replace the cable between the jack and fax machine?

You say "separate" second line. Was it run independently of Line 1 with different wiring and different jack(s)? If so, you have to trace the wires back to the NID (AT&T box) to make sure they're connected and not shorted.

If it's the same wiring for both lines, Line 1 uses the blue pair (or green & red) and Line 2 uses the orange pair (or black & yellow).

Plug the fax machine into one of the known working jacks to verify that it works.

Plug a phone into the fax jack to see if you hear dial tone.

 

Nothing changed, Rick. The line just went dead.

Did that already, but no difference.

I'm not sure, but it seems like it's the same wiring for both lines because the jack for the fax has the black and yellow lines attached.

Did that and then the fax machine works normally.

Did that and no dial tone on the working phone.

 

Unless it's a two-line fax machine, the B & Y wires (line 2) should be connected to the G and R terminals.

Disconnect the black & yellow and reconnect the green & red to the G and R terminals (line 1). Got dial tone? If so, go to the NID, pull the B &Y and put the jack right on the NID using a couple of short wires to the G & R terminals. If you don't have dial tone at the NID, call AT&T.

If you do have dial tone on Line 2 at the NID you'll have to trace the B & Y wires between the NID and the jack. The easiest way to check the line is to start with the house-side wires removed from the NID. Strip a bit of insulation off the B & Y and twist them together to short them. Now go to the jack and use a multimeter set to ohms to read the B & Y lines. You should read close to zero ohms. If not, there is a break in the line somewhere. If you do see zero ohms, undo the twist and read the jack again. If you see anything other than "open" or "OL" on the meter the line is shorted. Again, trace the line to find the short.