[7505, Conexant CX20590, Mic, Internal] No sound at all

mic dosn't work lenovo n581. neither pulse-audio, nor alsa . im have been using n581 3 month, appling several ubuntu upgrades, no result

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: alsa-base 1.0.25+dfsg-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.2.0-39.62-generic 3.2.39
Uname: Linux 3.2.0-39-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: PCH [HDA Intel PCH], device 0: CONEXANT Analog [CONEXANT Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: lm 2089 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'PCH'/'HDA Intel PCH at 0xe0610000 irq 44'
   Mixer name : 'Intel PantherPoint HDMI'
   Components : 'HDA:14f1506e,17aac033,00100003 HDA:80862806,80860101,00100000'
   Controls : 15
   Simple ctrls : 7
Date: Thu Mar 28 08:06:23 2013
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_AlsaRecordingTest: ALSA recording test through plughw:PCH failed
Symptom_Card: Built-in Audio - HDA Intel PCH
Symptom_DevicesInUse:
 2089 lm F.... pulseaudio
     PID ACCESS COMMAND
Symptom_Jack: Mic, Internal
Symptom_Type: No sound at all
Title: [7505, Conexant CX20590, Mic, Internal] No sound at all
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/22/2012
dmi.bios.vendor: LENOVO
dmi.bios.version: 5ECN40WW(V3.06)
dmi.board.asset.tag: No Asset Tag
dmi.board.name: Product Name
dmi.board.vendor: LENOVO
dmi.board.version: Mainboard version
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad N581
dmi.modalias: dmi:bvnLENOVO:bvr5ECN40WW(V3.06):bd10/22/2012:svnLENOVO:pn7505:pvrLenovoIdeaPadN581:rvnLENOVO:rnProductName:rvrMainboardversion:cvnLENOVO:ct10:cvrLenovoIdeaPadN581:
dmi.product.name: 7505
dmi.product.version: Lenovo IdeaPad N581
dmi.sys.vendor: LENOVO