no sound on Lenovo Ideapad 110

[Pierre Frenkiel <pierre.frenkiel@gmail.com>]

hi,
On my Lenovo Ideapad 110 laptop, with Debian Stretch, I have
sound neither with speaker nor headphone.
Here are some details:
- with WIndows 10, no problem, which means that the hardware is OK.
- with the Debian 9.1 kde live dvd, the sound works with the headphone,
  but not with the speaker.
- with the installed Debian 9.1 kde, no sound at all, with any program
  (including speaker-test)

I must add that pulseaudio runs correctly with the live dvd, but fails
on the installed system, although I copied the /etc/pulse content from
the dvd live.

   E: [pulseaudio] module.c: Failed to load module "module-alsa-sink" (argument: "device=default"): initialization failed.
   E: [pulseaudio] main.c: Module load failed.
   E: [pulseaudio] main.c: Failed to initialize daemon.


Googling gave me nothing useful. Has anybody an idea?

I find it abnormal that such a fundamental thing as sound is so
difficult to configure under Linux. It's that kind of problems which
makes difficult to convince people to abandon Windows for Linux.

best regards,
--
Pierre Frenkiel