Brother MFC-J3520 Service Manual page 151

(10)Release the Hook of the Scanner harness holder.
(11)Lift up the Scanner harness holder.
(12)Insert the section "A" into the Hole of the Document scanner unit.
Document scanner unit
Scanner
harness holder
(13)Move the Head/carriage unit manually to the position shown in the figure.
Head/carriage unit
Hook
Fig. 3-7
Fig. 3-8
3-31
Document
scanner unit
Hole
"A"
Scanner
harness
holder
Hook
Confidential