Symptoms
- Display is very faint or unreadable
- Screen shows random symbols or partial segments
- Calculator works only in bright light
Likely causes
- CommonWeak or dead batteryMost calculators run on small batteries that gradually weaken.
- CommonDirty or worn solar cellSolar-assisted calculators need adequate light on a clean panel to supplement the battery.
- PossibleContrast setting turned downA contrast dial or setting adjusted too low can look like a dead screen.
- PossibleCorroded battery contactsOld batteries can leak and corrode the contact springs.
- Less commonFailed LCD segmentPhysical damage or age can cause permanent display segments to fail.
What to do
- Adjust the contrast wheel or setting if your model has one.
- Replace the battery with a fresh one of the correct type.
- Wipe the solar panel clean if the calculator has one.
- Check battery contacts for corrosion and clean gently if present.
- Reset the calculator using its reset button or battery pull if it has one.
- Test in brighter light if the calculator relies partly on solar power.
- Replace the unit if the display still shows missing or garbled segments after a fresh battery.
Tools and parts
- Small screwdriver
Replacement batterySearch: “calculator button cell battery”
When to call a pro
Basic calculators are inexpensive enough that replacement usually makes more sense than professional repair for a failed display.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.