Brother MFC620CN Service Manual page 179

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.
(10) While pressing the idle pulley to the right, remove the CR timing belt from the carriage motor
pulley and idle pulley.
(11) Move the head/carriage unit to the left end of its travel.
(12) 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.
(13) Remove the CR timing belt from the head/carriage unit.
Head/carriage unit
Bosses
Cutouts
Idle pulley
CR timing belt
Engine unit
Idle pulley spring
5-41
Carriage motor pulley
Confidential