The mobile card suddenly has no signal, so you can read the short message. Is the card broken?

There is no signal in the mobile phone, which may be caused by the sim card, the hardware of the mobile phone, or the place where there is no service area or no signal.

If you want to judge whether the mobile phone card is broken, you can try this:

1, Settings-More Settings-Mobile Network-Network Operator, reselect the search network.

2. It is recommended to take out the SIM card, clean the SIM chip with an eraser, and then insert the SIM card into the mobile phone.

3. It is recommended to try to replace other SIM cards. See if your mobile phone and other people's mobile phones have a signal after the change. If not, it's a cell phone.

4. If it still exists, it is recommended to restore the machine to the factory settings and back up the data in the mobile phone in advance.

5. Call the card operator and ask the customer service to refresh the sim card background.

6. If the above cannot be solved, it is recommended to take it to the mobile phone repair station for inspection.

SIM card is (subscriber identity module), also known as subscriber identity card and smart card. GSM digital mobile phone can only use this card.

Digital mobile phone customer information, encryption key and user phone book are stored on the computer chip, which can be used to authenticate the identity of GSM network customers and encrypt the voice information when customers talk.

References:

Pacific IT Encyclopedia Mobile Android Channel-Zhongguancun Online SIM Card _ Baidu Encyclopedia