Make sure you are in an area with good cell signal. Check cell signal indicator at top left of the phone screen. Check if phone is in Airplane mode. If so, deactivate Airplane mode. Check if SIM card is inserted correctly. After entering the phone number, be sure to press the dial icon.

Check if battery is drained. If so, charge the battery for 5 minutes and then try to power on again. Remove any residue or debris found on phone or battery terminal with a soft and dry cloth. Check if the battery is seated correctly.

Check if you are in coverage service area. Check if your device is set on Airplane mode. If so, deactivate Airplane mode. Check if the SIM card is inserted correctly. Check that you have not blocked certain messages such as Advertisement or Messages from Anonymous Sender in Messaging Settings. If device memory is full, it cannot send and/or receive text messages. If device memory is full, delete any messages currently in your inbox and outbox to enable messaging.