Brother MFC-640CW - Manual (Page 165)

TROUBLESHOOTING AND ROUTINE MAINTENANCE 13 - 22
9
Pack the machine, the printed materials and additional parts
(handset, cords and CD) in the original carton as shown below.
Do not pack the used ink cartridges in the carton.
10
Close the carton.
If you are returning your machine to Brother as part of the
Exchange Service, pack only the machine. Keep all separate
parts and printed materials to use with your “Exchange”
machine.