ok thanks - well then it is a fax machine issue not the extension.
Now at the fax go through the following troubleshooting procedures.
First check the line connections
here is the link
Link
Good Luck...
You cannot receive a fax.
Q.Is the telephone line connected to the [LINE] side of the line connection terminal?
A.Reception is not possible when the telephone line is not connected properly.
Refer to the following item to connect properly.
How to Connect Telephone Cables (FAX-L100/FAX-L120) (See the relevant title in Related Information at the end of this page.)
Q.Is the memory full?
A.Print the data of documents from memory, and ask for retransmission.
Cannot receive a fax automatically.
Q.Is the machine set to receive automatically?
A.Refer to the following to set the receive mode to any mode other than [MANUAL].
How to Set the Receive Mode (FAX-L100/FAX-L120) (See the relevant title in Related Information at the end of this page.)
Q.Is the machine's memory full?
A.Wait for the machine to finish any fax or print jobs stored in the memory. Then ask the other party to resend the fax.
Q.Did an error occur during reception?
A.Refer to the following and print transmission/reception results reports and check for an error.
How to Print Out Transmission/Reception Results Reports (FAX-L100/FAX-L120) (See the relevant title in Related Information at the end of this page.)
Q.Is paper loaded in the machine?
A.Refer to the following to load paper in the machine.
How to Load Paper (FAX-L100/FAX-L120) (See the relevant title in Related Information at the end of this page.)
Q.Is the telephone line connected properly?
A.Refer to the following to make sure all line connections are secure.
How to Connect Telephone Cables (FAX-L100/FAX-L120) (See the relevant title in Related Information at the end of this page.)