Before you start
Do not begin with a broad reset. Check the following first so you can isolate the problem and avoid unnecessary data loss or reconfiguration.
- Check data allowance, account status and carrier outages
- Make sure mobile data is enabled for the correct SIM
- When abroad, verify roaming settings and country coverage
Critical diagnosis for this symptom
Separate signal indication, selected data SIM, account status, and APN checks.
Record the selected data line before changing dual-SIM settings.
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.
Understand the process
Safe step-by-step procedure
Work from the top and stop as soon as the issue is resolved. Read every confirmation screen before moving to a higher-impact action.
- 1Turn Airplane Mode on for about ten seconds, then off, to reconnect to the network.
- 2Check that mobile data is enabled and that the intended line is selected on a dual-SIM device.
- 3Restart the phone normally.
- 4Check carrier outage notices, maintenance, data limits and account restrictions.
- 5After a SIM change, verify activation, APN and eSIM status using the carrier’s official instructions.
- 6If the issue remains, consider a network-settings reset or contact the carrier.
Actions to avoid
- Entering APN details from an untrusted site
- Deleting an eSIM without a reissue method
- Assuming hardware failure in an area with no coverage
Prevention and preparation
- Know the eSIM reissue process and account credentials
- Before travel, confirm supported countries, charges and roaming conditions
Frequently asked questions
What if my screen looks different?
Labels and locations vary by OS, manufacturer, model and region. Use Settings search and check the manufacturer’s model-specific instructions.
What if I am unsure partway through?
Go back and confirm that no action has been committed. Do not proceed through an erase or account-change warning until you understand it.
What if the problem remains?
Test another connection or accessory where relevant, verify backups, then contact the manufacturer or carrier through official support.