Hi Manospe,
Thank you for using the Support Forum. Please make sure that you have a clear phone line, plug in a regular phone to the line you have going to the fax and listen to the dial tone and then dial a number, make sure there is no static, popping or clicking on the line. If the line is not clear please contact the the phone company. If the line is good please try modifying the transmission speed. If that does not help please consider contacting your local support centre.