ALC655 Sound problem

[david walcroft]

Hi,
   I cannot get sound from mplayer, sound in KDE,streaming audio (xmms), 
Sound card detection works but mplayer is mute with the error:-

Checking audio filter chain for 22050Hz/2ch/s16le 22050Hz/2ch/s16le...
AF_pre: 22050Hz/2ch/s16le
Could not open/initialize audio device -> no sound.
Audio: no sound

How do you 'open/initialize' a sound device.
The chip is an 'RealTek ALC655 (VT8233/A/8235/8237 AC97'

   Thanks   david