HP 3550 - Manual (Page 135)

11. To reattach the lower rear door (rear output bin), hold the door at a 45º angle, and fit the
peg into the round hole on the right side.
12. Press the ridges on the tab on the left side of the door, and fit the peg into the round hole.
13. Close the lower rear door (rear output bin).
ENWW Replacing supplies and parts 123