Not Turning On
Casio Casio Calculator
Severity: CriticalWhat Does This Error Mean?
A Casio calculator that will not turn on usually has dead batteries or needs a hard reset. Replace the batteries first. If that does not work, press the reset button on the back.
Affected Models
- Casio fx-991EX
- Casio fx-991ES Plus
- Casio fx-CG50
- Casio fx-9860GII
- All Casio calculators
Common Causes
- Batteries dead
- Batteries inserted incorrectly (wrong polarity)
- Calculator needs a hard reset
- Solar panel insufficient light (solar-powered models)
- Display contrast set to minimum (screen appears blank)
- Hardware failure
How to Fix It
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Replace the batteries.
Scientific calculators use LR44 or AAA batteries. Graphing calculators use AAA batteries. Make sure polarity (+/-) is correct.
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Press the reset button on the back.
Use a paperclip or pin to press the small RESET button on the back of the calculator. This clears the memory and resets the calculator.
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For solar models: make sure there is enough light.
Solar calculators need light to power on. Try under a bright lamp if the room is dim.
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Adjust screen contrast.
If the calculator turns on but the screen appears blank, the contrast may be at minimum. Hold SHIFT and press the up arrow repeatedly to increase contrast.
Frequently Asked Questions
Does resetting erase my programs?
Yes. A hard reset erases all stored data, programs, and settings. The calculator returns to factory defaults.
How long do calculator batteries last?
Scientific calculators: 2-3 years with normal use. Graphing calculators: 3-6 months of regular use (they use more power for the larger screen).