MFC-420CN

FAQs & Troubleshooting

FAQs & Troubleshooting

I am experiencing problems sending a fax, what can I do?

If you are experiencing problems sending faxes, please follow the instructions below:


  1. Verify that the date and time are displayed on the LCD.

    1. If the LCD displays the date and time, continue to Step 2.

    2. If the LCD displays an error message, check "FAQ & Troubleshooting" for further information on that error.

    3. If the LCD shows Telephone, any key pressed will not respond. Please hang up the extension phone and/or press the Hook key.

    4. If the LCD is blank, first verify that the unit is not in the OFF mode. Press and hold the ON/OFF (Power Save) key located on the control panel until the date and time appear on the display. If the display remains blank, verify that the power cord is connected. If the power cord is connected to a surge protector or power switch, remove the cord from the device and connect it directly to the outlet. If date and time now appear, there is a problem with your surge protector or power switch. If the display is still blank, try a different electrical outlet. If the display still remains blank, your machine may require service.
  1. Verify that the machine is connected directly from the wall to the jack labeled LINE on the unit.
  1. Verify if your Brother machine has a dial tone. For more information, please refer to "How can I verify if my Brother machine has a dial tone?".

    If there is a dial tone, continue to Step 5. If there is no dial tone, continue to Step 4.
  1. Verify that the wall jack has dial tone. Disconnect the unit from the wall jack and connect the known working regular telephone and telephone line cord directly to the wall jack. Lift the handset of the telephone and listen for dial tone.

    1. If there is a dial tone from the wall jack, your unit may require service.

    2. If there is no dial tone from the wall jack, there is a problem with your line and you need to contact your local telephone company for assistance.
  1. Verify that your document(s) are the correct size. The document(s) must be between 5.8 inches (148 mm) and 8.5 inches (216 mm) wide and 5.8 inches (148 mm) and 14 inches (356 mm) long.

If you must send a document longer than 14 inches (356 mm)long, click here to obtain contact information for the appropriate Brother Customer Service Center for assistance.


  1. Verify that you have inserted the document(s) face up into the ADF with the top edge first.
  1. When placing the document(s) in the Automatic Document Feeder (ADF), verify that the Fax mode key is illuminated in green and the LCD changes to Res: xxxxxxx (the desired resolution setting).
  1. Be sure to adjust the paper guides on the sides of the ADF to fit the width of your document. This insures the document will feed straight and will prevent jams.
  1. Verify that you are not inserting more documents than the ADF can hold. The ADF can hold up to 10 pages of standard 20lb (75 g/m2) paper, feeding each one individually through the fax machine. If you are using paper heavier than 20lb (75 g/m2), you must feed each sheet individually to prevent jams.

DO NOT use curled, wrinkled, folded or ripped paper, or paper with staples, paper clips, paste or tape attached. DO NOT use cardboard, newspaper or fabric.


  1. When sending a fax manually, be sure to wait to hear the fax tones of the receiving fax unit before pressing Black (Mono) Start or Color (Colour) Start key.
  1. If you are having problems sending a fax to one number, verify that the number you are dialing is a working fax number and that you hear fax tones when the receiving machine answers.

If you continue to have problems sending faxes after following the steps listed above, your unit may require service.

If your question was not answered, have you checked other FAQs?

Have you checked the manuals?

If you need further assistance, please contact Brother customer service:

Related Models

MFC-420CN, MFC-5440CN, MFC-5840CN, MFC-640CW

Content Feedback

To help us improve our support, please provide your feedback below.

Step 1: How does the information on this page help you?

Step 2: Are there any comments you would like to add?

Please note this form is used for feedback only.