No network after inserting the SIM card:
1, because you do not know your mobile phone model, it is recommended that you can find your mobile phone frequency band online, and then check whether the SIM card you use conforms to the mobile phone frequency range;
2. It is recommended that you try it after shutting down and restarting, and try it after reinserting your SIM card;
3, it is recommended that you replace the network environment, it is not ruled out because of the surrounding network coverage;
4, it is recommended that you go to your phone (system) Settings -- (more) -- Wireless and network -- Mobile network -- access point name to change the access point to use comparison;
5, it is recommended that you replace your SIM card to use, do not exclude your SIM card caused by abnormal;
6, back up your mobile phone data, restore factory Settings; Invalid send for repair.
Select Use Wireless in Wireless Settings, or turn off data.