[Satellite L745, Conexant CX20585, Speaker, Internal] No sound at all

[Geoffrey P.]

Headphones work just fine. Internal speakers do not work. There was a brief moment where the drum sound played on log-in one time but then the speakers have never output anything again.

NOTE: A few releases ago: 14.04 LTS?!? (Before 16.04, in any case) the sound worked perfectly. It hasn't worked since that time. I recently did a fresh install of Ubuntu 18.04 to se if it would clean up the problem. It only corrected the issue very briefly.

1) Ubuntu 18.04.2 LTS
2) alsa-base 1.0.25+dfsg-0ubuntu5
3) Sound output through internal speakers
4) No sound output through external speakers. The only sound output possible is via headphones. Headphones confirmed to work normally with sound output.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 4.15.0-45.48-generic 4.15.18
Uname: Linux 4.15.0-45-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: geoffrey 1971 F.... pulseaudio
CurrentDesktop: communitheme:ubuntu:GNOME
Date: Mon Feb 11 17:11:25 2019
InstallationDate: Installed on 2019-02-11 (0 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_DevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: geoffrey 1971 F.... pulseaudio
Symptom_Jack: Speaker, Internal
Symptom_Type: No sound at all
Title: [Satellite L745, Conexant CX20585, Speaker, Internal] No sound at all
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/26/2012
dmi.bios.vendor: INSYDE
dmi.bios.version: 2.60
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Base Board Product Name
dmi.board.vendor: Intel Corp.
dmi.board.version: Base Board Version
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: OEM Chassis Manufacturer
dmi.chassis.version: OEM Chassis Version
dmi.modalias: dmi:bvnINSYDE:bvr2.60:bd06/26/2012:svnTOSHIBA:pnSatelliteL745:pvrPSK0YU-0D102G:rvnIntelCorp.:rnBaseBoardProductName:rvrBaseBoardVersion:cvnOEMChassisManufacturer:ct10:cvrOEMChassisVersion:
dmi.product.family: Intel_Mobile
dmi.product.name: Satellite L745
dmi.product.version: PSK0YU-0D102G
dmi.sys.vendor: TOSHIBA