Plantronics Blackwire c720 stopped working

[Olafur Ingolfsson]

When plugged in i hear a womans voice, "Power off", then nothing.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: alsa-base 1.0.25+dfsg-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.8.0-44.66~precise1-generic 3.8.13.25
Uname: Linux 3.8.0-44-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.8.0-44-generic.
ApportVersion: 2.0.1-0ubuntu17.13
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: PCH [HDA Intel PCH], device 0: ALC269VC Analog [ALC269VC Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: olafuri 3089 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'PCH'/'HDA Intel PCH at 0xf3530000 irq 49'
   Mixer name : 'Intel PantherPoint HDMI'
   Components : 'HDA:10ec0269,17aa21fb,00100203 HDA:80862806,80860101,00100000'
   Controls : 50
   Simple ctrls : 17
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw unknown'
   Mixer name : 'ThinkPad EC (unknown)'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Tue Dec 1 09:14:09 2015
MarkForUpload: True
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Title: USB sound card not detected
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/30/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: G7ET94WW (2.54 )
dmi.board.asset.tag: Not Available
dmi.board.name: 2356LPG
dmi.board.vendor: LENOVO
dmi.board.version: Win8 Pro DPK TPG
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrG7ET94WW(2.54):bd04/30/2013:svnLENOVO:pn2356LPG:pvrThinkPadT430s:rvnLENOVO:rn2356LPG:rvrWin8ProDPKTPG:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2356LPG
dmi.product.version: ThinkPad T430s
dmi.sys.vendor: LENOVO
mtime.conffile..etc.modprobe.d.alsa.base.conf: 2015-12-01T09:01:08.538626