Casio CASSIOPEIA A-20 Service Manual & Parts List page 59

4. Unscrew two screws (30) to remove the terminal holders. Remove both battery terminal.
Terminal holder
5. Remove the terminal wire, then remove the main board.
6. When you replace K-film (35), stick K-spacer (34) on the "ON" key on new K-film.
* This is to prevent from accidentaly turning the computer off.
K-spacer
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