Firstly, ensure the Fax cable (typically brown colour) is connected at both ends. Secondly, try Phoning the Fax number from a Normal Handset. You should hear a ‘Screeching Fax’ tone after a few rings. If this sound doesn’t occur there is potential an issue with the Fax Line not the machine. You can test the line by Faxing 1300 368 999 or 03 9640 0999, you should receive a Telstra Title Return Fax. There have been issues in the past where they do not respond.