A phone or tablet feature that has completely stopped should be checked for a disabled permission or setting before assuming hardware failure. For iPhone cellular data, first test a call and public website in two locations with Wi-Fi off and VPN disabled.
What this covers
- iPhone cellular data with this exact failure state
- Diagnosis across carrier outage/account versus SIM/eSIM, coverage, VPN and per-app data settings
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: attach to the carrier network and route allowed app traffic at the provisioned service level.
Isolate the component boundary
ReversibleTest a call and public website in two locations with Wi-Fi off and VPN disabled. Test the same feature in a different app that uses it, and with recently installed apps disabled or in Safe Mode. Boundary to separate: carrier outage/account versus SIM/eSIM, coverage, VPN and per-app data settings.
Correct only the proven cause
ReversibleInstall carrier settings, correct the selected line/data permission or contact the carrier. 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. Seek carrier or emergency support when service loss affects urgent calling.
Evidence ledger
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