Canon imageRUNNER ADVANCE 4551i Service Manual page 1004

5.
NOTE:
Do not remove the spacers together with the screws. If
they come off, be sure to put them back where they were
originally installed.
4x
6.
CAUTION:
Be sure to place the removed Main Controller PCB 1
flatly.
Reason: Due to the protruded plate, the PCB may be
deformed if work is performed while it is placed at an
angle.
2x
NOTE:
The removed screw is used at late procedure.
991
9. Installation