Brother HL-4200CN - Manual (Page 139)

ROUTINE MAINTENANCE AND CONSUMABLE REPLACEMENT 7 - 13
3
Unpack a new transfer roll cartridge and grip the
orange tabs as shown.
4
Insert the pins at both ends of the transfer roll
cartridge into the bearings inside the printer, and
gently push the roll into the printer.
5
To lock the transfer roll cartridge into the printer,
push down on the tabs until you hear a click.
6
Close the front cover.