Brother MFC-3340CN Service Manual page 127

Removing the head/carriage unit and CR timing belt
NOTE: During the removal or installation job for the head/carriage unit, take care not to
contaminate the CR encoder strip or PF encoder disk with grease applied to the head/carriage unit.
NOTE: Do not disassemble the old type of the head/carriage unit. Always handle it together with
the carriage PCB and head flat cables.
(8) While pressing the idle pulley to the right, remove the CR timing belt from the carriage motor
pulley and idle pulley.
(9) Move the head/carriage unit to the left end of its travel.
(10) Align the bosses on the head/carriage unit with the cutouts in the engine unit and lift the
head/carriage unit up and off the engine unit.
NOTE: Do not touch the print 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, clean
them with a special-purpose cleaning stick and liquid.
(11) Remove the CR timing belt from the head/carriage unit.
Carriage PCB
Bosses
Head/carriage unit
Cutouts
Idle pulley
CR timing belt
ngine unit
Idle pulley spring
5-29
Carriage motor pulley
Confidential