Iphone keeps displaying information from the secondary card.

1. First, enter Settings, Applications, All, SMS, and clear data. Restart the phone to see if there is a signal problem.

2. Secondly, check whether the number of the information center is correct, and click Information, the menu button in the lower left corner, Settings and Information Center. The number of centers in different operators and regions is different. Please contact the network operator for confirmation.

3. Then try to replace other SIM cards and upgrade the firmware.

Finally, if you still can't send SMS through the above methods, take the purchase invoice, maintenance card and machine to the after-sales center for testing.