Brother MFC-J3520 Service Manual page 158

(27)Move the Head/carriage unit to the position where the Hooks of the Head/carriage
unit are aligned with the Cutouts in the CR guide rail.
(28)Take out the Head/carriage unit from the CR guide rail.
Note: Do not touch the head nozzles (the printing ends) or ink supply ports (to which
ink supply tubes are connected) of the Head/carriage unit; doing so will not only
stain your hands with ink but also damage the nozzles and supply ports. If you do
touch them though, perform a head cleaning operation.
CR guide rail
(29)Remove the Carriage flat cable from the section "A" of the Head/carriage unit.
Carriage PCB
Head/carriage unit
Hooks
Cutouts
Fig. 3-19
Fig. 3-20
3-38
Head/carriage unit
28
27
Carriage flat cable
"A"
Confidential