My 2-year old Lenovo B41-30 last night suddenly stopped putting out audio ... was watching TV On Demand when both video and sound stopped.

 

Closed video and browser, and tried again ... got video but no sound.

 

This morning, went through all the usual audio checks and tests, viz. stop/restart service, uninstall drivers and reinstall etc etc.  Uninstalled all RealTek and Dolby apps .. reboot/reinstall etc etc.  All devices look OK and reported as working.

 

Now all I get is a regular clicking beat through the speakers or headphone.  Also, even if I mute the speakers, they are on again after a reboot (stayed muted previously).

 

Hardware?  Software?  Suggestions?