Line out and headphones audio output keep swithing causing crackles in sound

[George Panagiotopoulos]

There is an audio crackle every few seconds when I use headphones. Under the sound tab in settings the "Line Out-Built-in Audio" device flickers at the exact moment there is a crackle. By opening the pavucontrol audio manager I can see the "Built-in Audio Analog Stereo" output device port keeps switching to "Headphones (unplugged)" from "Line Out(plugged in)" for an instance.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 4.15.0-38.41-generic 4.15.18
Uname: Linux 4.15.0-38-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.4
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: george 10877 F.... pulseaudio
 /dev/snd/controlC2: george 10877 F.... pulseaudio
 /dev/snd/controlC0: george 10877 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Wed Oct 31 20:21:09 2018
InstallationDate: Installed on 2018-10-09 (21 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaPlaybackTest: ALSA playback test through plughw:PCH failed
Symptom_Card: Built-in Audio - HDA Intel PCH
Symptom_Jack: Green Line Out, Rear
Symptom_PulseAudioLog:
 Οκτ 31 18:49:55 LinuxPC dbus-daemon[775]: [system] Activating via systemd: service name='org.freedesktop.RealtimeKit1' unit='rtkit-daemon.service' requested by ':1.38' (uid=1000 pid=1298 comm="/usr/bin/pulseaudio --start --log-target=syslog " label="unconfined")
 Οκτ 31 18:49:58 LinuxPC dbus-daemon[775]: [system] Activating via systemd: service name='org.bluez' unit='dbus-org.bluez.service' requested by ':1.44' (uid=1000 pid=1298 comm="/usr/bin/pulseaudio --start --log-target=syslog " label="unconfined")
 Οκτ 31 19:49:44 LinuxPC dbus-daemon[775]: [system] Activating via systemd: service name='org.bluez' unit='dbus-org.bluez.service' requested by ':1.211' (uid=1000 pid=10877 comm="/usr/bin/pulseaudio --start --log-target=syslog " label="unconfined")
Symptom_Type: Underruns, dropouts, or "crackling" sound
Title: [To be filled by O.E.M., Realtek ALC887-VD, Green Line Out, Rear] Underruns, dropouts or crackling sound
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/23/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F4
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: Z170-HD3P-CF
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF4:bd11/23/2015:svnGigabyteTechnologyCo.,Ltd.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnZ170-HD3P-CF:rvrx.x:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: To be filled by O.E.M.
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Daniel van Vugt (vanvugt)]

Please try:

1. Booting Ubuntu 18.10 on the machine to see if this bug is already fixed:
   http://releases.ubuntu.com/18.10/

2. A different set of headphones.

3. Other audio output methods like the built-in speakers or Bluetooth.

Do any of those help?

[George Panagiotopoulos (georgepanag)]

Upgrading to Ubuntu 18.10 didn't seem to help. Using a different set of headphones also didn't work. Other audio sources work fine. Unplugging the headphones from the line out port in the back panel of the computer and plugging it in the front headphones port stops the crackling and the flickering in the settings. Headphones work fine now.

[Daniel van Vugt (vanvugt)]

Thanks.

It sounds like there is a bad connection in the port on the back panel. That would explain both crackling and flickering settings. The flickering would be Ubuntu quickly detecting spurious insertion/removal or connection/disconnection of the headphones. So this sounds like a hardware problem with that port.