Updated answer for January 2019
There is a new single deb installer package on the Brother website that installs both printer and scanner drivers. This makes installation much easier.
- Download the 'Driver install tool`.
- Open bash terminal and navigate to download folder.
Unzip the file...
gunzip linux-brprinter-installer-2.2.1-1.gz
(version number will probably change, so watch for that).
Change to superuser or use sudo for the following commands:
bash linux-brprinter-installer-*.*.*-* MFC-J825DW
Agree to prompts and select to use ip address (11 or I when I did it) , then enter the printers ip address when prompted. You can find the address on the printers touch screen display from the 'network' menu if you don't know it.
Old answer, which concerned what to do if you entered the wrong IP address, however it is probably outdated and I suggest trying to rerun the Driver install tool and re-entering the ip address again when prompted.
I think this is a case of only being stuck until you ask for help. Soon after posting this I decided to check the ip addesses of the printer and scanner. Sure enough I'd entered a different ip for each one somehow. Since the printer worked and the scanner didn't, I made the assumption that the scanner had the wrong one.
To correct this I had to enter the following line at the command prompt:
brsaneconfig4 -r SCANNER
This command removed the scanner with the incorrect ip address. Then I simply added it back again, making sure the ip address was right this time.
brsaneconfig4 -a name=SCANNER model=MFC-J825DW ip=192.168.3.3
Note: You should probably set the scanner up to a fixed ip in the router, otherwise you may have problems later on when it gets assigned a different ip when the router is reset.
Unfortunately none of the solutions above worked for my Brother DCP-7045N, but just the normal standard installation:
Download packages from http://solutions.brother.com/
Install doing
sudo dpkg -i --force-all brscan3-0.2.5-2.i386.deb
sudo dpkg -i --force-all brscan-skey-0.2.1-1.i386.deb
Check with dpkg -l | grep Brother
brsaneconfig3 -a name=SCANNER model=DCP-7045N ip=192.168.1.101
Check with brsaneconfig3 -q | grep DCP-7045N
I hope it does it for you too!
Best Answer
from this thread, post #25
https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/1728012
add these two symbolic links
(ie you need to copy each command above; line by line; paste into a terminal; hit the ENTER key and move to second line ..) re-boot ....... any joy?