2. If the mobile phone or SIM card is damaged, you can change the machine for testing to see if the mobile phone or SIM card is faulty.
3. The current position is a signal blind area or there is no signal suddenly. You can test it in another place and pay attention to whether the cell phone signals of other users around you are normal.
4. The mobile phone card is in arrears. At this time, you have to pay the arrears before you can turn it on.
5. The mobile phone number is used abnormally and then the service is suspended, for example, the number is used for illegal activities.
6. When roaming abroad or in Taiwan, Hong Kong and Macao, you need to open the international roaming function or roam in Taiwan, Hong Kong and Macao before you can use it.
7. When the total traffic generated by surfing the Internet in the current month reaches the upper limit of the package traffic, the system will automatically turn off the Internet access function or speed-limiting network according to the upper limit rules of your package traffic, and then automatically resume opening next month.
Apple's mobile phone traffic can't be solved:
1, open the settings option in the phone.
2. Find GM or Settings, which is also a gray gear, pull it down and click Restore Network Settings.
Maybe the flight mode is turned on or some software is turned on, so cellular mobile data cannot be used. The specific solution is as follows.
Turn off flight mode:
1. Check whether there is an airplane icon in the upper left corner of the phone interface. If so, turn off the flight mode.
2. Open the settings, find the flight mode, and close it.
Cellular mobile data cannot be used when some software is turned on:
1. Open the settings and find the cellular mobile data.
2. After clicking, you can see options such as cellular mobile data and 4G.
3, continue to pull down, pull to the bottom, you can see the usage of cellular data, there is a switch at the back, you can click to open the software traffic directly.