Check these first
Do not assume the cause from the symptom alone. First determine whether the issue affects the whole phone, one app, one connection, or one accessory. Work from low-impact checks toward recovery or repair.
- Determine whether all callers or only certain numbers are affected
- Review Focus, silent mode, and silence-unknown-callers settings
- Place a real test call from another phone
Critical diagnosis for this symptom
Separate blocking, focus modes, spam filtering, forwarding, and voicemail behavior.
Record whether the issue affects one caller or all callers.
Escalate with device, OS, error, and reproduction details when the issue persists after restart, controlled comparison, and update checks, or when physical damage, abnormal heat, account suspension, or carrier provisioning is suspected.
Narrow down the cause
| Scope of the issue | Where to check next |
|---|---|
| Only one app is affected | Check app permissions, updates, storage, cache, and reinstall options |
| The whole phone is affected | Check restart, system updates, free storage, and system settings |
| Other devices have the same issue | Check the network, service, charger, or accessory |
| The issue began after a drop or liquid exposure | Avoid repeated power or charging attempts and contact official support |
See the troubleshooting flow
Safe step-by-step process
Complete one step at a time and test after each change. Do not change several settings at once.
- 1Toggle Airplane mode, then restart the phone to register with the mobile network again.
- 2Review Focus or Do Not Disturb, ringtone volume, vibration, and allowed contacts.
- 3Check blocked numbers, spam-call filters, and settings that silence unknown callers.
- 4Review call forwarding, voicemail, the selected dual-SIM line, and the default calling app.
- 5Check carrier outages, account status, required calling features, OS updates, and carrier settings.
- 6If calls from several sources still fail, ask the carrier to inspect incoming-call routing and line provisioning.
Actions to avoid
- Leaving all spam protection disabled after testing
- Changing forwarding without recording the original destination
- Assuming the problem is fixed without a real incoming-call test
Prevent the issue from returning
- Allow critical contacts through Focus modes
- Run incoming and outgoing tests after major call-setting changes
Frequently asked questions
What if my screen looks different?
Menu names and locations vary by OS, manufacturer, model, region, and software version. Use the Settings search field and check the manufacturer guide for your exact model.
When should I stop troubleshooting?
Stop as soon as the issue is fixed. Change one setting at a time so you can identify what solved the problem and reverse it if necessary.
What should I do if the issue remains?
Record how to reproduce it, verify your backup, and contact the manufacturer, carrier, or app provider most closely related to the problem.