If you manually set up a network connection error, your phone will not be able to register to the normal network services. To correct this, select the "Please select Automatically" option in the "Available networks" Settings area, follow these steps:
Figure 1:
1. Under the Standby page, click "Application".
2. Click "Set".
3. Click "More Networks" under the "Connect" option.
4. Click on "Mobile network".
5. Click on "Network Operator".
6. Click "Please auto Select" to search automatically.
When you are done, the triangle exclamation icon in the upper-left corner disappears and the "registered on the network" appears.
Tips:
If the problem persists after the above operation, please try the following:
1. Restart the phone attempt.
2. Replace other SIM card attempts.
3. Restore the factory setup attempt after backing up the data. (Standby page-application-Settings-account-Reset-Restore factory settings-Reset device-delete all)
4. The equipment will be sent to Samsung Service Center for troubleshooting by engineers.
Friendly Tips
If you do not use this method to resolve your mobile network is not available, we can try to restore the phone factory settings or change a SIM card to try it.