我在 Thinkpad X201 上运行 ubuntu 16.04。我遇到的问题是，无论音频来源是什么（Rhythmbox、Chromium 或 Firefox 中的 YouTube、VLC 或内置视频播放器），声音几分钟后就会消失。我不确定内部音频出了什么问题，也不知道从哪里开始诊断。重启后问题似乎消失了，但又回来了。
dmesg 中的声音相关问题
[ 3.280231] snd_hda_codec_conexant hdaudioC0D0: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[ 3.280233] snd_hda_codec_conexant hdaudioC0D0: hp_outs=2 (0x1c/0x19/0x0/0x0/0x0)
[ 3.280234] snd_hda_codec_conexant hdaudioC0D0: mono: mono_out=0x0
[ 3.280235] snd_hda_codec_conexant hdaudioC0D0: inputs:
[ 3.280237] snd_hda_codec_conexant hdaudioC0D0: Internal Mic=0x23
[ 3.280239] snd_hda_codec_conexant hdaudioC0D0: Mic=0x1b
[ 3.280240] snd_hda_codec_conexant hdaudioC0D0: Dock Mic=0x1a
[ 3.281704] snd_hda_codec_conexant hdaudioC0D0: Enable sync_write for stable communication
[ 3.338059] input: HDA Intel MID Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input11
[ 3.338156] input: HDA Intel MID Dock Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input12
[ 3.338277] input: HDA Intel MID Dock Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input13
[ 3.338367] input: HDA Intel MID Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input14
[ 3.338452] input: HDA Intel MID HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input15