Sharp AR-5316 Service Manual page 12

2) Loosen the copy lamp unit wire fixing screw.
3) Manually turn the mirror base drive pulley and bring No. 2/3 mirror
base unit into contact with the positioning plate. At that time, if the
front frame side and the rear frame side of No. 2/3 mirror base unit
are brought into contact with the positioning plate at the same time,
the mirror base unit parallelism is proper. If one of them is in contact
with the positioning plate, perform the adjustment of 4).
Wire fixing screw
AR-5316 ADJUSTMENT 6-5
4) Loosen the set screw of the scanner drive pulley which is not in
contact with No. 2/3 mirror base unit positioning plate.
5) Without moving the scanner drive pulley shaft, manually turn the
scanner drive pulley until the positioning plate is brought into contact
with No. 2/3 mirror base unit, then fix the scanner drive pulley.
6) Put No. 2/3 mirror base unit on the positioning plate again, push the
projections on the front frame side and the rear frame side of the
copy lamp unit to the corner frame, and tighten the wire fixing screw.