Realtek ALC888 - Sound works, no microphone - clean Natty install

[Flavio Capobianco]

Sound worked fine on Maverick install. After a fresh install of Natty, I notice that sound comes from both speakers and headphones when Analog Output is selected as Connector under Sound Preferences. Microphone does not work, not even after fiddling around alsamixer's Captures, Input sources, etc.

alsa-base:
  Installed: 1.0.24+dfsg-0ubuntu1
  Candidate: 1.0.24+dfsg-0ubuntu1

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: alsa-base 1.0.24+dfsg-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: vladis 1258 F.... pulseaudio
 /dev/snd/pcmC0D0c: vladis 1258 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'SB'/'HDA ATI SB at 0xf0000000 irq 16'
   Mixer name : 'Realtek ALC888'
   Components : 'HDA:10ec0888,10250293,00100202 HDA:14f12c06,10250093,00100000'
   Controls : 28
   Simple ctrls : 16
Card1.Amixer.info:
 Card hw:1 'HDMI'/'HDA ATI HDMI at 0xcfdec000 irq 19'
   Mixer name : 'ATI RS690/780 HDMI'
   Components : 'HDA:1002791a,00791a00,00100000'
   Controls : 4
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Mon Jun 27 23:29:37 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: alsa-driver
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/09/2009
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: V1.09
dmi.board.name: JV50TR
dmi.board.vendor: Acer
dmi.board.version: Rev
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: None
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvrV1.09:bd12/09/2009:svnAcer:pnAspire5542:pvr0100:rvnAcer:rnJV50TR:rvrRev:cvnAcer:ct10:cvrNone:
dmi.product.name: Aspire 5542
dmi.product.version: 0100
dmi.sys.vendor: Acer

[Launchpad Janitor (janitor)]

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