1 The first possibility is that we turn the volume key down, or to mute, in this case, in the "Settings"-"voice and Vibration"-"volume"-"Voice call volume" In the adjustment volume, you can solve this problem.
2 The second situation is if we upgraded the system or installed software, resulting in the phone does not sound, because the software conflict so the latest download software uninstall can be normal to call it!
3 If the uninstall software has not been able to solve the problem, you need to restore the factory settings, backup good data, and then click to restore the factory can solve the problem.
4 If your mobile phone still has a warranty, it is best to get the after-sale inspection, to see whether it is a software problem or a good hardware.
5 If your phone is already over the warranty, but brush the latest system to try.
