I am also getting the following in dmesg, not sure if it's related:

[  373.182370] snd_hda_intel 0000:00:03.0: IRQ timing workaround is activated for card #0. Suggest a bigger bdl_pos_adj.
[  394.402892] perf: interrupt took too long (2501 > 2500), lowering kernel.perf_event_max_sample_rate to 79750
[  615.276757] perf: interrupt took too long (3127 > 3126), lowering kernel.perf_event_max_sample_rate to 63750

Hi Kosarzhevsky,

From your attached message, it seems there is no HDA analog audio on your system. Do you playback with HDMI/DP audio? Which command do you use to do the playback?

Thanks,
Libin

Created attachment 232161 [details]
attachment-19680-0.html

Hello,

I don't have HDMI/DP audio speakers to test. I have tried KDE5/Plasma and
it's silent.
There is pre-installed Windows OS on the PC, the audio works there
flawlessly.
Let me know if you need more information or diagnostics to run.


On 6 September 2016 at 05:35, <bugzilla-daemon@bugzilla.kernel.org> wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=153901
>
> Libin Yang <libin.yang@intel.com> changed:
>
>            What    |Removed                     |Added
> ------------------------------------------------------------
> ----------------
>                  CC|                            |libin.yang@intel.com
>
> --- Comment #2 from Libin Yang <libin.yang@intel.com> ---
> Hi Kosarzhevsky,
>
> From your attached message, it seems there is no HDA analog audio on your
> system. Do you playback with HDMI/DP audio? Which command do you use to do
> the
> playback?
>
> Thanks,
> Libin
>
> --
> You are receiving this mail because:
> You are on the CC list for the bug.
> You reported the bug.
>

From your informatioin:

Your system is broadwell. And there is a HDMI/DP audio and a USB audio.

If you want to playback through USB, please do the following test to see if it works:
$ alsamixer -c1
in the alsamixer, please unmute and set the volume to a proper value, and then run:
speaker-test -Dplughw:1,0 -c2 -t wav

If you want to playback through HDMI, please do the following test to see if it works:
$ alsamixer
in the alsamixer, please unmute, and then run:
speaker-test -Dplughw:0,num -c2 -t wav
num can be 3, 7 or 8 based on which HDMI/DP port you are connecting.

BTW: your kernel is a little old to recognize it is a BDW.

just for the records

I just bought the same hardware a few weeks ago and also ran into the same sound issue with debian stretch (kernel 4.8).

After upgrading the UEFI-Bios to N17ET90W (1.90) plus additional loading  of "OS-optimized" Defaults Settings, the sound issue disappeared.

The firmware can be updated with the n17ur44w.iso from lenovo website.
Unfortunately you need an external usb-cdrom, as the Bios does not recognize the Bootloader on the iso image if put to usb-sticks.

Please note that you might need to restore the bootloader after loading Default Settings in the Bios. I'd bet that a Windows Bootloader Entry would have been left untouched.