before checking the telephone wire, we first checked the telephone device to assess what is the main problem what we should do. After assessing the problem we concluded that there are no dial tone on the telephone line.
first we check the telephone if it is good and working. In our case we use another telephone for testing and other telephone wire with connectors to check if the device is working. We also check the I/O if it is in good condition and working. We checked the wires connected in the I/O if it still connected. then we assured that all the device is working we went to the full out box where we have the connection of lines going to PABX panel.
We find the wire of that telephone that has trouble if hard to find its wire you can use tone tracer. after finding the wire and the connection we check the condition and if it is connected properly.
If it’s still connected properly and and there still trouble use another spare wire. in our case we have another pair of wire in that telephone line and it is color coded. after changing the wire test the telephone again. If the telephone is still not working go to the main PABX panel and check the connection and try to replace wire with the spare with the spare wires.
if you already used all spare wire and there still no dial tone on the telephone line maybe all the wires on the line were damaged or disconnected.