Canon BJ-230 - Manual (Page 51)

5. Fit the ink cartridge over the yellow mounting base with the print
head facing down. (When installed correctly, the label on the
cartridge will be upside down.)
6. Push the lock lever down until it snaps into place.
CAUTION: Avoid touching the yellow mounting base on which you place
the cartridge--especially the circuit board on the side of the mounting base
and the film cable that extends from the cartridge holder.