audio only in one channel 12.04

[Mike]

Works fine in headphones, but through my MacBook's onboard speakers only the left one works; and it's kinda quiet.
It worked fine from the initial install (a daily build from 11/21), but since the "distribution upgrade" that came along when Precise Pangolin's alpha was available, the right speaker dropped out.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: pulseaudio 1:1.1-0ubuntu3
ProcVersionSignature: Ubuntu 3.2.0-3.8-generic 3.2.0-rc4
Uname: Linux 3.2.0-3-generic i686
NonfreeKernelModules: wl
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.90-0ubuntu1
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: michael 6780 F.... pulseaudio
 /dev/snd/controlC0: michael 6780 F.... pulseaudio
 /dev/snd/pcmC0D0p: michael 6780 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xc1d00000 irq 43'
   Mixer name : 'Cirrus Logic CS4206'
   Components : 'HDA:10134206,106b0b00,00100301'
   Controls : 21
   Simple ctrls : 11
Card1.Amixer.info:
 Card hw:1 'NVidia'/'HDA NVidia at 0xc1080000 irq 16'
   Mixer name : 'Nvidia GPU 0a HDMI/DP'
   Components : 'HDA:10de000a,10de0101,00100100'
   Controls : 20
   Simple ctrls : 4
Date: Thu Dec 8 19:59:50 2011
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20111121)
SourcePackage: pulseaudio
UpgradeStatus: Upgraded to precise on 2011-12-06 (2 days ago)
dmi.bios.date: 07/26/10
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP61.88Z.0057.B0C.1007261552
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-F22586C8
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro6,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F22586C8
dmi.modalias: dmi:bvnAppleInc.:bvrMBP61.88Z.0057.B0C.1007261552:bd07/26/10:svnAppleInc.:pnMacBookPro6,2:pvr1.0:rvnAppleInc.:rnMac-F22586C8:rvrMacBookPro6,2:cvnAppleInc.:ct10:cvrMac-F22586C8:
dmi.product.name: MacBookPro6,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.

[Mike (bild85)]

Just performed a fresh install of 12.04 32-bit (nice installer!) and the same problem exists - sound only out of the left on-board speaker.

[Launchpad Janitor (janitor)]

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

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 12.04 (precise) reached end-of-life on April 28, 2017.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test.

[Launchpad Janitor (janitor)]

[Expired for pulseaudio (Ubuntu) because there has been no activity for 60 days.]