A phone or tablet feature that has completely stopped should be checked for a disabled permission or setting before assuming hardware failure. For iPhone touchscreen input, first remove charger/case/protector for a test and draw across the full screen in a simple app.
What this covers
- iPhone touchscreen input with this exact failure state
- Diagnosis across one app and screen region versus protector, moisture, accessory and display hardware
What it does not cover
Try in this order
0 of 4 completedCapture the exact failure state
ReversibleCheck whether the feature is grayed out, missing from settings entirely, or present but unresponsive when used. Expected behavior: register taps, swipes and multi-touch consistently across the display.
Isolate the component boundary
ReversibleRemove charger/case/protector for a test and draw across the full screen in a simple app. Test the same feature in a different app that uses it, and with recently installed apps disabled or in Safe Mode. Boundary to separate: one app and screen region versus protector, moisture, accessory and display hardware.
Correct only the proven cause
ReversibleRestart/update or replace the proven accessory; service fixed dead zones. Re-enable the permission or setting, or update/reinstall the one app where it fails.
Verify and stop safely
ReversibleConfirm the feature works from a cold restart in at least two different apps. Stop for a lifted display, swelling, cracks, heat or liquid exposure.
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