The US version of the locked 5C cannot connect to the 3G network using the China Unicom 3G card and cannot send text messages.

The mobile phone cannot access the Internet normally and cannot send messages. Please check the following situations:

1. Confirm whether there is a network. It is recommended to use it in a place with strong signal;

2. Check whether the USIM card is inserted properly. If it is inserted but still cannot be used, it is recommended to go to the business hall to check whether the USIM card is faulty or replace the card for testing;

3. Check whether the mobile phone has If there is a problem, I suggest you change the device to test.

4. Check whether there is still phone credit in the account. If the balance is insufficient, you need to recharge before you can use it.

5. Confirm whether the mobile phone parameters have been set.