What is the reason why Gomez Smart Watch has no service?

Show the possible causes and solutions of "no service":

1. Flight mode, just turn it off. Or the signal is weak, consult the operator.

2. No recognition (such as telecom SIM card for mobile phone)

3. Whether the check card trough is loose or deformed, send it for repair.

4. Restart (if the battery is detachable, it is best to take out the battery and restart it)

5. Put the SIM card on other devices and test whether the SIM card is faulty.

6. Software or system reasons. Brush machine, it is best to use official ROM.

7. Hardware failure, sent for repair.

Above, for reference.