Same problems as others...

Disable the FAX auto-answer

Press the FAX button

1. Menu/Set, 0, 1
2. Use the up/down arrow to select Receive mode to be "Manual"
3. Press Menu/Set
4. Press Stop/Exit
   

Manual
http://ec1.images-amazon.com/media/i3d/01/A/man-migrate/MANUAL000057875.pdf

put a phone wire from the line jack on the machine to the wall. like this you should be able to send

to receive put the machine in fax only receive mode and only connect the phone wire when you know there is a fax coming in bacause in this mode it will answer every call like a fax

Follow the way.

1. plug on you phone connection with your all in one machime.
2. Then On the all in one machine.
3. Dial no getting tone from other side put your paper in top side copier place.
4. receiving fax make your fax receiving setting automatic. in will came out.

*** But remember before use it you must activate your phone connection for sending & receiving fax. FOr these you have to contact with you phone connection company."

Thanks & waiting for your feedback

Here'a a link for the manual on-line

it should not give you any problem if you configure dial up properties of MFC

here you might find an answer:

http://welcome.solutions.brother.com/bsc/public/us/us/en/faq/faq_top.htm?reg=us&c=us&lang=en&prod=mfc240c_all

plz contact brother hotline of your country ( www.brother.com )because there are so many diffrent telephone standards which might affect a good working of the fax abillity.

So if you have no noise, its a prob of the tele company not of the mfc!
Or did the tel company change to another tel standard instead of your former type?
You have to talk to the tel company to get that clear. Ask for the line standard bein g used (ISDN, normal, or a special tcpIp).

When you got the info call brother hotline of your country for support. They will help you with that prob.

First make sure your line cable is plugged into the correct place. Most Brother machines have a plug for Line and a plug for Extension (EXT), make sure it's plugged into "Line".

Go into the menu on your Brother machine and select Fax, then Setup Receive and then select Easy Receive. This will usually solve most recieve problems.
Brother machines come with s default of 4 rings before they will answer, make sure none of your other devices (such as an answering machine) are set to a lower number of rings or the fax machine will never grab the line.

If you have distinctive ring, make sure you have it set up in the machine. There is a section in the owners manual for setting up discinctive ring.

If the machine grabs the line and goes through the motions but nothing comes out on the page (no black print) then make sure you are using a Brother ink cartridge (not refilled or generic) and print out the test page using the "ink" button. Allow the machine to clean a few times and see if the test page prints out correctly. If you are using refills or a generic black, you might have premanently damaged the print head. In this case take it to a service centre to have the head tested.

I realise this is an old question but I recently had a similar issue with our MFC-5860CN not receiving faxes and displaying the "Mn1" code. As it turns out "Mn1" means the machine is set to manual receive and was therefore not automatically receiving faxes. You will need to locate the "Receive Mode" option in the menu and change it to "Fax Only" or "Fax / Tel". Unfortunately I dont know what could have caused the turning off and on that the OP mentioned. I'm a little late to the party but I hope this info can help someone else!