Hi @BasilDV  I have tried the telephone 2 port and the message is still the same 'Check Tel Line' and I have tested it with a second working telephone and I get the same error message. I also have checked the data from the modem itself and thats alright and the telephone 1 light is on and the telephone 2 light also comes on when the telephone cord is plugged in, i've changed the telephone cord (2pin) and I have also tested it with a 4pin telephone cord and changed the modems telephone cord (4pin). The error message stays the same 'Check Tel Line'  ... View more