Xiaomi note9 SMS has no sound.

1. Please back up data, enter recovery mode, clear cache, clear user data and clear all data. When restoring the backup, do not restore the settings and third-party security software in the mobile phone. Try to use it normally.

2. If it still doesn't work, I suggest you brush the whole package again with a line brush according to the following method. You can refer to the following brushing tutorial:

1. First, you download a MIUI line brush package suitable for your model in Xiaomi official website. This is the link:/topic-mirom.html.

2. During downloading, please back up the data, enter recovery (shutdown, press and hold the volume increase+power on key to enter recovery), and empty the cache, user data and all data. Install the computer driver and download a miflash brush tool. This is the driver installation link:/thread-504332-1-1.html.

3. After everything is ready, please use the six-line brush according to official website's brushing tutorial, which is the official brushing tutorial:/thread-3104435-1.html.

4. If you are not familiar with brushing, you can refer to the video tutorial of brushing made of rice flour:/v _ show/id _ xnteymjq1mzi4.html.

Thank you for your support and wish you a happy life!

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