1, it may be that the network coverage where the mobile phone is located is not good or the signal is blocked. In some closed indoor environments, such as densely spaced buildings, mobile phone signals may be blocked, resulting in signal deterioration, and the coverage of operator networks varies according to different regions. In this case, we can go out and test whether the cell phone signal can return to normal or use the cell phone signal condition of the same operator's calling card to judge whether it is caused by network coverage problems.
2. It may be that the network settings of the mobile phone are wrong. Open the "Settings" function of the mobile phone, find the "VPN" function to adjust and set the network, or restore the network settings and try again.
There is no signal on the mobile phone. Sometimes there may be something wrong with the calling card. In this case, you can take out the calling card and observe whether the metal surface is dirty or oxidized, which may affect the reading of the signal. You can keep your calling card clean before you try to insert it. And if your phone card is cut and the shape is not standard, it may also affect the reading of the signal. At this time, only a normal calling card can be replaced, and you can bring your personal ID card to the operator's business hall to reissue a standard calling card.
(The above situations and methods are applicable to most mobile phone models of Huawei brand. )