Speaker stopped working after installing WP 8.1 Dev Preview...!!! Please Help...!!!

[WPCentral Question]

Lumia 720 speaker stopped working,,,,
dont know why.

it was working properly after installing for about 10-12 hours,
but after then, it stopped working,
my volume down key is also not working.

i tried HARD reseting my fone. but now its dead.

its not getting started.
please help....!!!

thanks in advance.

 

[xandros9]

Are you saying your phone is now completely dead?

My inclination is to think it was terribly timed hardware failure.

 

[Anojan Sivam]

I don't know why ? But downgrade it to WP 8