Chat with Bother support for adding Brother MFC7860DW as network scanner

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Found available agent: Hugo  .  You can chat now.
Hugo  : Good morning!
Hugo  : How may I help you?
Jimmy: hi
Jimmy: good morning
Jimmy: I have two MFC7860DW in our office
Jimmy: When I installed CC4, it can only find one machine, not the second one
Jimmy: I can use IE to access both printers
Jimmy: I can also add both printers
Jimmy: but my computer can only find one scanner, ont the other
Hugo  : Mmm have you tried installing over it?
Jimmy: I went to my-computer->network, I can see both machines, but when I tried to install the one has problem, only printer was installed
Jimmy: What do you mean " installing over it"
Hugo  : Yes when you install it will only install one driver for the printer, and one for the scanner
Hugo  : you could add another printer driver manually but not another scanner
Hugo  : you need to isntall the disc again
Hugo  : but when you get to the connection type both machines should show up, select the one that is not already installed
Jimmy: I wil call the good machine: brother A, and the bad machine Brother B.
Jimmy: I tried to run the Windows wizard for adding scanner, but the wizard can only find Brother A
Hugo  : did you connect Brother B to the network? can you print to brother B?
Jimmy: Yes, I can use IE to remote control both A and B
Jimmy: on that web interface, ther is an option: "find devices"
Jimmy: I clicked that, from Brother B, I can see BRother A and the status is ready
Jimmy: from Brother A, I can find brother B as well, but the status is blank
Hugo  : yes what's the operating system on the computer?
Jimmy: The computer is Windows 7
Hugo  : ok and can you tell me what the LCD screen of Brother B is currently saying?
Jimmy: it is sleep
Hugo  : ok on brother B press Menu, 6, 2, 1, 2 and let me know the address
Jimmy: The printer is connected with cable
Jimmy: Brother A is connected with wireless network
Hugo  : network cable or usb cable?
Jimmy: when I tried to connected Brother B to the wireless network, I kept getting message that WLAN router cannot be detected
Jimmy: Brother B has both USB and network cable connected
Jimmy: The computer with USB cable connected has no problem to access Brother B
Hugo  : ok then press Menu, 6, 1, ,1 2 on brother B and let me know the address
Jimmy: but another computer tried to connect to it via network failed
Jimmy: the address is 192.168.40.10
Hugo  : ok, you'll need to install the mfl-pro suite again
Hugo  : either from the disc or online
Hugo  : select Wireless Connection and check Custom Install
Hugo  : when you get to a point that says Select the machine you want to isntall
Chose the one with 192.168.40.10 next to it
Hugo  : when the computer restarts you'll have both options in control center
Jimmy: OK, I will try it, thanks very much
Hugo  : No problem!
Hugo  : Let us know if there is any issue
Jimmy: Since I am not in front of the printer, I will do it later.
Jimmy: Yes, I will
Jimmy: Have a good day

Note: I think disable and enable the LAN port did the trick. I disable the LAN port and enable the WLAN posrt and try to use wireless network. Unfortunately the machine was not able to connect to my wireless network, so I have to change back to the wired network the next day. This time, when I click "find devices" for the other Brother's web interface, I can see the status of the problem machine, which was blank the other day.
I did follow the instructions given by Hugo, installed ControlCenter 4 and used Custom Install and manually put IP address. This time there is no problem to add that brother machine.