Canon BJC-250 - Manual (Page 62)

6
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 BJ
cartridge holder.
Make sure the BJ cartridge is
pressed against the back of the
holder Fit the BJ
cartridge
over the
yellow
mounting base
with the print
head facing
down.
7
Make sure the cartridge is
secure, and the lever locks
into place.
Make sure there is no
resistance when you press on
the lock lever; it should lock
easily into place.
If you hear any snapping
noises or feel any resistance
as you press on the lever,
remove the BJ cartridge and
try again. Press the lock
lever down
completely; do
not use
excessive force.