my sony walkman nwz-s638f has lost its sound suddenly, the volume controls do not work when you press up or down and they do not show on screen. Headphones have been checked in other devices to eliminate them from the problem. Everything else is working fine, ive tried charging it up fully to see if it would help and ive pressed the reset button but nothing changes. The volume button does not feel loose and still makes the quiet clicky sort of sound when you press it. When the 'Hold' function is on and I press the volume button the 'cancel hold' screen comes up - so the button is still connected.
