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Replacing the Battery

fx-991MS sold in the US and Canada: For safety reasons, please do not replace the battery yourself. Always leave battery replacement up to an authorized CASIO service center.


The battery needs to be replaced after a specific number of years. Also, replace the battery immediately after display figures become dim.

A low battery is indicated by a dim display, even if contrast is adjusted, or by failure of figures to appear on the display immediately after you turn on the calculator. If this happens, replace the battery with a new one.


Important!

Removing the battery will cause all of the calculator's memory contents to be deleted.

1. Press (OFF) to turn off the calculator.

2. On the back of the calculator, remove the screws and the cover.

3. Remove the battery, and then load a new battery with its plus (+) and minus (-) ends facing correctly.

4. Replace the cover.

5. Initialize the calculator: (CLR)(All).

Do not skip the above step!

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