vivo x9用联通卡没有4G网络是因为没有把联通卡设为主卡。
vivo x9设定主卡的方法:
首先打开手机,找到手机的系统设置图标,点击进入设置;
![](https://iknow-pic.cdn.bcebos.com/b3119313b07eca809ab151229a2397dda04483bb?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
现在来到设置菜单找到手机的“双卡管理”点击进入双卡管理;
![](https://iknow-pic.cdn.bcebos.com/d009b3de9c82d1588cda31748b0a19d8bd3e429e?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
现在就来到了双卡管理菜单,主副卡是可以直接设置的现在卡1是主卡,也可将卡2设置为主卡,直接点击卡2下面的原点;
![](https://iknow-pic.cdn.bcebos.com/71cf3bc79f3df8dc8b8be754c611728b46102844?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
软件提示切换时,将导致数据业务、打电话等功能不可用,是否继续切换,单击“确定;
![](https://iknow-pic.cdn.bcebos.com/8b82b9014a90f603ee01f4823212b31bb151ed46?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
是否将默认移动数据切换至卡2?,单击“切换”;
![](https://iknow-pic.cdn.bcebos.com/b17eca8065380cd79082ca28aa44ad3458828152?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
现在软件正在切换卡槽,等待切换完成卡2就变为主卡了。
![](https://iknow-pic.cdn.bcebos.com/0ff41bd5ad6eddc43eb2dc3e32dbb6fd53663399?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)