If you can't get the symptoms clear enough to write them down in black and white, you will have trouble explaining it to any other troubleshooter.
Wires can break.
Segment the problem and solve the segments before you solve the big picture. Keep in mind that there is a standard terminology problem that always exists around the telephone industry. Frequently these are not single wires. In DS-1, these are Transmit pair and Receive pair. Of the Transmit pair, there is a Tip wire and a Ring wire.