On my Mythbuntu 12.04.2 HTPC, my USB microphone (Logitech AK5370) works for a few seconds, then stops producing signal from audio input. The system recognizes it there, it just stays mute. This happens on all USB ports. It has worked fine for months.
I`m confident it's not the hardware because the microphone works fine with Win7 and also on other computers.
$ uname -a
Linux KISE-066 3.5.0-34-generic #55~precise1-Ubuntu SMP Fri Jun 7 16:25:50 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
$ lsusb
Bus 001 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 005 Device 002: ID 1532:001c Razer USA, Ltd RZ01-0036 Optical Gaming Mouse [Abyssus]
Bus 005 Device 003: ID 0556:0001 Asahi Kasei Microsystems Co., Ltd AK5370 I/F A/D Converter
Bus 006 Device 002: ID 04ca:002a Lite-On Technology Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 003: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 001 Device 004: ID 046d:c525 Logitech, Inc. MX Revolution Cordless Mouse
Re-install of Mythbuntu is impracticable.
I tried the fix in this question (changing gstreamer settings) but it didn't work.
After every change, the mic would work as seen on Pulse Audio Volume Control for a few seconds, then the "level" on the level caught at the few seconds when it stopped working.
I installed Audacity to monitor the microphone's input level.
With the settings ALSA > default > AK5370:USB Audio (hw:1,0): Line 0 the level meter shows the mic working.
Using a "trick" from the old days, I re-installed the following...
gstreamer0.10-pulseaudio (version 0.10.31-1ubuntu1.2) will be re-installed
libcanberra-pulse (version 0.28-3ubuntu3) will be re-installed
libpulse-mainloop-glib0 (version 1:1.1-0ubuntu15.3) will be re-installed
libpulse-mainloop-glib0:i386 (version 1:1.1-0ubuntu15.3) will be re-installed
libpulse0 (version 1:1.1-0ubuntu15.3) will be re-installed
libpulse0:i386 (version 1:1.1-0ubuntu15.3) will be re-installed
libpulsedsp (version 1:1.1-0ubuntu15.3) will be re-installed
libpulsedsp:i386 (version 1:1.1-0ubuntu15.3) will be re-installed
libusb-0.1-4 (version 2:0.1.12-20) will be re-installed
libusb-0.1-4:i386 (version 2:0.1.12-20) will be re-installed
libusb-1.0-0 (version 2:1.0.9~rc3-2ubuntu1) will be re-installed
paman (version 0.9.4-1ubuntu3) will be re-installed
paprefs (version 0.9.10-0ubuntu1) will be re-installed
pavucontrol (version 0.99.2-1build1) will be re-installed
pavumeter (version 0.9.3-1ubuntu2) will be re-installed
pulseaudio (version 1:1.1-0ubuntu15.3) will be re-installed
pulseaudio-module-gconf (version 1:1.1-0ubuntu15.3) will be re-installed
pulseaudio-module-x11 (version 1:1.1-0ubuntu15.3) will be re-installed
pulseaudio-module-zeroconf (version 1:1.1-0ubuntu15.3) will be re-installed
pulseaudio-utils (version 1:1.1-0ubuntu15.3) will be re-installed
usbutils (version 1:005-1) will be re-installed
...and rebooted.
No help.
I have discovered that after closing and reopening Pulse Audio Volume Control, the microphone volume level will show the microphone working fo a few seconds, then "freezing".
???