What should I do if I just changed my 4s Unicom card and there is often no service?

There is no service displayed on the mobile phone, so it is suggested to click the method to check:

1, whether the SIM card is inserted correctly.

2. Whether to insert the wrong SIM card, such as the standard version of Unicom SIM card.

3. Enter the hardware test to see if the SIM card works normally (enter *#*#64663#*#* in the dialing interface). If the SIM card status is normal, go to step 5; If the status is unknown, go to step 4.

4. Try to change a different SIM card. If the status is still unknown during hardware testing, it is recommended to go to the maintenance point for testing. If the detection status is normal, the operator is advised to replace a SIM card (SIM card may be aging).

5. Whether the network type is correct and whether the operator chooses automatic. (Unicom preferred 3G, mobile preferred 2G, and telecom preferred automatic)

6. If the network type of the mobile phone is CDMA automatic, the problem can be solved by changing the network type to "WCDMAPreferred" in the mobile phone information (* # * # 4636 # * *).

7. Whether there is no signal in this area. You need to check whether other mobile phones on the same network have a signal.

8. Back up the data, brush to the latest system version and try again.

9. If the above methods still can't help the user solve the problem, please go to the nearby maintenance point for maintenance and testing.