why have I no sound on my microsoft 640 mobile

[Windows Central Question]

since I downloaded the anniversary edition my phone is silent I am missing emails phone calls ir any thing else to day with sound

 

[RumoredNow]

First step is try a Soft Reset.

Hold the Power and Volume Down buttons util the phone vibrates and reboots (about 10 seconds). This clears out the RAM and cache. It may solve the glitch.

Next check all relevant settings...

If that does not work, make a back up and Factory Reset.