Porteus

pulseaudio can be reset:
guest@porteus:~$ pulseaudio -k && pulseaudio -Dvvv
I: [pulseaudio] main.c: Daemon startup successful.
But the command is unsuccessful: no sound!
Are there other options?
Can someone help?

Try this in a terminal as guest:

pulseaudio -k && pulseaudio -Dv --log-target=newfile:pulse.log

This will restart pulseaudio and send the output to /home/guest/pulse.log.......it may show something when the sound quits. You can increase the verbosity, but I found the above gave lots of info.

Thanks for the replies.
The problem is solved.
It was a very insidious(!) hardware error.
(Switching between internal speakers and headphone jack)