Xiaomi's mobile phone can be used, but it can't be answered. The number you dialed is busy. What happened?

It is recommended to check by clicking:

Whether the SIM card is inserted correctly.

② Whether the SIM card is inserted incorrectly, such as the standard version inserted with the telecom SIM card, etc.

(3) Enter the hardware test to check whether the SIM card works normally (just 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 replace 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 selection is automatic. (Unicom preferred 3G, mobile preferred 2G, and telecom preferred automatic)

⑥ If the network type of telecom mobile phone is CDMA automatic, the problem can be solved by changing the network type to "WCDMA priority" 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.