shown here is the fx-120, but the
process is the same with any of these green-screen style models including
the fx-29, fx-39. the older cases of the al-10
and al-8 are also similar.
remove the batteries and screw the small fixing screw(s) inside. this
model has another fixing screw holding a small panel in the back too.
remove all these.
shown opposite are the positions of the six fixing lugs that hold the
case together. these need to be carefully popped open before the
back of the case can be removed revealing the circuit board.
the rear plastic case will not completely separate as there is a wire
to the battery compartment terminals, although the wire is normally long
enough to put the case just to one side.