1. Please avoid using magnetic/metal protective shell, magnetic bracket or magnetic sucker.
If your mobile phone uses a metal protective case, a magnetic protective case, a magnetic bracket or a magnetic sucker, it is recommended that you take it off and try it out. Metal and magnetic materials easily interfere with the signal, resulting in no signal in the mobile phone.
2. Please confirm whether the SIM card is disabled.
Please search in the settings and enter the SIM card management to ensure that the SIM card switch is turned on. Disabling the SIM card will cause the signal bar to display no signal (when a single card is inserted) or only one card signal (when a dual card is inserted).
3. Please troubleshoot the mobile phone card.
It is recommended that you install other SIM cards of the same operator into your mobile phone for inspection. If the signal is normal, there may be something wrong with your mobile phone card. I suggest you go to the operator's business hall to replace a new mobile phone card.
If your mobile phone card is cut by hand, it may affect signal reading due to nonstandard shape and poor contact. It is recommended that you bring your personal ID card to the operator's business hall to apply for a standard mobile phone card.
Dirty or oxidized mobile phone cards will also affect the reading of signals. I suggest you keep your mobile phone card clean.
4. Please eliminate the network reasons.
(1) Please try to change the current location.
In some closed indoor environments, such as densely spaced buildings, cell phone signals may be blocked, resulting in no signal.
The network coverage of operators varies according to different regions, and some regions may have insufficient coverage capacity, resulting in no signal on mobile phones.
If your mobile phone has no signal in a specific area, or friends around you use the calling card of the same operator, it may be caused by the poor network quality in your area, and you can return to normal after switching to other places.
Please try resetting APN.
Incorrect APN settings will affect the normal use of the network.
Method 1:
A. click settings;
B. Enter "APN" in the top search bar, and click the name of the access point (APN) to enter the mobile data page;
C. Click the name of the access point (APN) to enter the APN page;
D. open three or four point buttons in the upper right corner;
E. click reset to default settings.
Method 2:
If your mobile phone is EMUI 10.0 or above, or HarmonyOS system version 2.0 or above, you can also follow the following steps:
A. click settings;
B, click the mobile network, and then click the mobile data;
C. Click the name of the access point (APN) on the mobile data page to enter the APN page;
D. open three or four point buttons in the upper right corner;
E. click reset to default settings.
Warm reminder:
If your mobile phone is EMUI 8. X or EMUI 9. X system, you can follow the following steps:
Settings Wireless and Network Mobile Network Access Point Name (APN); Open the three point buttons in the upper right corner and reset to the default settings.
③ Please try to restore the network settings.
Tip: Restoring network settings will restore all network settings, including WLAN, mobile data network and Bluetooth settings, and will not delete other data or modify other settings.
(4) Please restart your phone or try switching flight modes.
Please update your mobile phone system to the latest version and try again.
Please back up your data in advance (third-party communication applications need to be backed up separately) and update your mobile phone system to the latest version.
If the above investigation can't solve your problem, I suggest you contact Huawei's customer service hotline (950800) for more help, or back up your data in advance (third-party communication applications need to be backed up separately), and bring relevant purchase vouchers to the nearby Huawei customer service center for testing.