PCI/internal sound card not detected

[Markus Strenn]

my sound was working in xenial. with internal intel sound. without any change it stopped working, no soundcard found.
update to bionic didn't change anything :(

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 4.15.0-34.37-generic 4.15.18
Uname: Linux 4.15.0-34-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.3
Architecture: amd64
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CurrentDesktop: ubuntu:GNOME
Date: Tue Sep 25 14:16:55 2018
InstallationDate: Installed on 2016-03-10 (929 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Title: PCI/internal sound card not detected
UpgradeStatus: Upgraded to bionic on 2018-09-24 (0 days ago)
dmi.bios.date: 03/22/2017
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0906
dmi.board.asset.tag: Default string
dmi.board.name: PRIME Z270-A
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0906:bd03/22/2017:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnPRIMEZ270-A:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer