[X555LA, Realtek ALC3236, Speaker, Internal] No sound when switching from HDMI to internal audio

[Laoise]

When switching from HDMI audio to internal speakers, the sound stops working altogether. The only way to prevent this is to enter the settings while still connected to HDMI and select "Speakers - Built in audio" as the output. Disconnecting from HDMI without doing this stops any audio playing through internal speakers or headphones (including the speaker test in settings). It was expected that disconnecting a HDMI output would automatically change the sound output to internal speakers. Attempting to click "Speakers - Built in audio" when disconnected from HDMI has no effect, the only way to remedy this is to reconnect the device to HDMI and select the above output. This means if the device is removed from HDMI and taken to another location, no sound can be used until a HDMI output can be found and connected. Rebooting has mixed effects, on one occasion a reboot restored the sound, however on all others it does not. The test tones DID play during the debug process however this is the only sounds I can get to play. The version of Ubuntu is 18.04 LTS.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 4.15.0-22.24-generic 4.15.17
Uname: Linux 4.15.0-22-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC1D0c: laoise 1485 F...m pulseaudio
 /dev/snd/controlC1: laoise 1485 F.... pulseaudio
 /dev/snd/pcmC0D7p: laoise 1485 F...m pulseaudio
 /dev/snd/controlC0: laoise 1485 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Thu May 31 14:35:41 2018
InstallationDate: Installed on 2017-04-13 (412 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:PCH successful
Symptom_Card: Built-in Audio - HDA Intel PCH
Symptom_Jack: Speaker, Internal
Symptom_PulsePlaybackTest: PulseAudio playback test successful
Symptom_Type: No sound at all
Title: [X555LA, Realtek ALC3236, Speaker, Internal] No sound at all
UpgradeStatus: Upgraded to bionic on 2018-05-12 (19 days ago)
dmi.bios.date: 08/14/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: X555LA.308
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: X555LA
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrX555LA.308:bd08/14/2014:svnASUSTeKCOMPUTERINC.:pnX555LA:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnX555LA:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.family: X
dmi.product.name: X555LA
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.