HP Elite 8100 SFF and ubuntu 16.04 sound

I've got this HP Elite 8100 SFF (circa 2011) and everything seems to work, but no sound.

In System settings/Sound I get a "Dummy Output."

dmesg | grep snd

tells me that

[ 11.737424] snd_hda_intel 0000:00:1b.0: no codecs found!

Man, I wish things would just work...


!!DMI Information
!!---------------

Manufacturer: Hewlett-Packard
Product Name: HP Compaq 8100 Elite SFF PC
Product Version:
Firmware Version: 786H1 v01.05
Board Vendor: Hewlett-Packard
Board Name: 304Ah



!!Soundcards recognised by ALSA
!!-----------------------------

--- no soundcards ---


!!PCI Soundcards installed in the system
!!--------------------------------------

00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev
05)


!!Advanced information - PCI Vendor/Device/Subsystem ID's
!!-------------------------------------------------------

00:1b.0 0403: 8086:3b56 (rev 05)
Subsystem: 103c:304a


edit: I get the same exact thing with Knoppix 7.7, snd_hda_intel 0000:00:1b.0: no codecs found!

I got a usb docking port that has usb sound built-in and that seems to work just fine so far, just plug in and it works.

edit: I updated the bios from 1.05 to 1.13 and it didn't make any difference. Still no sound.