Casio JD-5500 Service Manual page 13

When the unit does not work properly ...
The unit may stop working properly after it is subjected to strong electrostatic charge or strong impact. If this
happens, first check to make sure that the main batteries and back-up battery are correctly installed, and then
perform the following operation.
1. Loosen the screw that holds the back-up battery compartment cover in place, and remove the cover.
2. Use a thin, pointed object (like a paper clip) to press the RESET button inside the battery compartment
cover. When you do, the "Reset?" screen should appear.
3. Make sure that the pointer is located at "No," and then press EXE. The "Check time!" message should
appear on the display.
4. Press EXE again, and then use the Timekeeping Mode to set the current time.
5. Replace the battery compartment cover.
— 12 —