While many homes and offices are converting their phone lines from analogue to digital, they are experiencing issues concerning their fax machines, which stop working unless they are converted to digital. This is accomplished with a line converter that converts the analogue signal that your fax machine sends to a digital signal that your phone line requires.
Unplug fax machine. Whenever working on electronic devices, it is always safest to unplug them to remove them from their power source.
Remove phone line from the fax machine.
Plug in new telephone patch line into the "Line In" port on the back of the fax machine.
Install a digital line converter. Plug in the line coming from the fax machine into the "Line In" port and plug in the line coming from the wall telephone jack into the "Line Out" jack on the digital line converter. Plug in the power cord into the digital line converter.
Send a test fax. Once the digital line converter is installed, you will be able to use your analogue fax machine to send and receive faxes over your digital phone lines.
If you are unable to send or receive faxes after this process, check to make sure that your phone lines are plugged into the correct ports of the digital line converter and that it is powered on.