Brother MFC 7840W - Manual (Page 66)

Chapter 7
52
Changing the remote codes
7
The preset fax receive code is l51. The
preset telephone answer code is #51. If you
are always disconnected when accessing
your external TAD, try changing the
three-digit remote codes, for example ###
and 999.
a
Make sure you are in Fax mode .
b
Press Menu 2, 1, 4.
Setup Receive
4.Remote Codes
c
Press a or b to choose On (or Off).
Press OK.
d
If you chose On in c, enter the new Fax
Receive Code.
Press OK.
e
Enter the new Telephone Answer Code.
Press OK.
f
Press Stop/Exit.