CANON FAX MACHINE WILL SEND BUT WON'T RECEIVE

SOURCE: Fax machine will send out but will not receive any

The majority of the time, when you can send but not receive, it is a phone line issue and not the machine. Extremely rare does a machine send and not receive. So here goes the things to try and the reason. 1, Make sure the phone jack is in the "Line" jack and not the external phone jack. Believe it or not, that is the number one issue with sending and not receiving.
Next, plug a phone into the jack that the fax machine is plugged into and see if there is static.
You want to be sure in the fax \settings and advanced settings that the ECM mode is ON, and that Junk Fax ius turned OFF, Junk Fax being on will stop almost all fax from comming in.
Now, the phone line. Here is the explaination of why that can be the problem. When you send a fax, you manually make the connection to the line. When you press send a relay flips and connectes you to the phone line, therefore you have made pretty much a mechanical connection enabling the phone line, and therefore you can send.
Now, when you have an incoming fax, several conditions must me met to make the handshake and therefore connect and receive. These all have to be right in order to properly receive. The phone line voltage mist be high enough, the phone line current must be correct and there can not be much decibel loss over the line. You are making a signal connection, all those conditions must be right to receive a fax. Think of it like a TV remote with batteries that are almost dead, It still send out some signal, but it will not change channels or change the volumn,etc etc. Same principle. If the signal to the incoming fax is weak, chances are it will not connect.