What's wrong with my sim card plugged into my mobile phone? Always shows no SIM card!

One: the SIM card is not detected, which makes the SIM card unrecognizable.

Problem phenomenon:

The status bar above the phone shows an icon of a SIM card with an exclamation mark on it.

Mobile phones with two SIM cards can only recognize 1 SIM card, and only one card signal is displayed in the status bar, and the other SIM card is not prompted.

Solution:

1. Please confirm whether the SIM card is placed correctly and whether the gap of the SIM card corresponds to the card slot. If it is a non-standard SIM card or a self-cutting card, it may not match the card slot. It is recommended that you replace the standard SIM card.

2. Please confirm whether the surface of SIM card is dirty. I suggest you clean it up simply. If the connection point of the SIM card is badly worn, or it becomes discolored and cannot be cleaned (the metal surface may be oxidized), it may lead to poor contact. It is recommended that you replace it with a standard SIM card.

3. Please try to insert other normal SIM cards to confirm whether there is any problem. If there is no problem, your SIM card may be damaged. It is recommended that you change your SIM card in the business hall of the nearest network operator.

If you still can't read the card, please back up the information in advance and bring the relevant purchase certificate to the nearby Huawei customer service center for maintenance.

Two: SIM card is detected and recognized, but the status bar shows no network.

Problem phenomenon:

The status bar above the phone shows the icon of the signal bar, but the signal is displayed as an X.

Solution:

1. Please confirm whether the corresponding SIM card has been enabled in dual card management.

2. I suggest you restart your mobile phone. Some models do not support hot plug, so you need to restart to search the network again.

3. If all the mobile phones around using the same carrier network have problems, the local network may be abnormal. I suggest you try calling from another place or consulting the operator.

4. Dual 4G models or some mobile customized models are not supported. As a secondary card, there is only 2G/3G network. If the local 2G/3G network is not covered, there is no signal.

5. Please install other SIM cards normally used by the same operator into the same card slot of this machine. If there is no problem, it may be a SIM card problem. It is recommended that you contact the operator for replacement.

6. Some models do not support CDMA network. If you insert the mobile phone card of a CDMA operator (such as the SIM card of China Telecom), there may be no signal on the mobile phone.

7. If the domestic version of the mobile phone is used overseas, or the overseas version of the mobile phone is used in China, there may be a mismatch between the mobile phone and the carrier's frequency band. If your SIM card is roaming internationally, please drop down the status bar, press and hold the mobile data icon to enter the mobile network setting interface, select the network operator, turn off the automatic selection, and the mobile phone will start to search for the operator manually.

8. At present, Huawei mobile phones don't support two telecom cards, and dual telecom cards can only stand by after the auxiliary card turns on the VoLTE function (VoLTE is not supported overseas).

9. It is recommended that you search "Restore Network Settings" in the settings to try to restore network settings (note: WLAN and Bluetooth related records will be deleted).

If there are still problems, please back up the information in advance and bring the relevant purchase vouchers to the nearby Huawei customer service center for maintenance.