I sometimes have the problem that I can't hear any sound on my Dell XPS13 with Ubuntu 16.04. I have a Logitech G930 connected to it. When I open pavucontrol it is stuck at "Establishing connection to PulseAudio. Please wait..." I have been following the Ubuntu Audio Problems Guide (german version is here: https://wiki.ubuntuusers.de/Sound_Problembehebung/#Soundsystem ) and found the following:
$ cat /proc/asound/cards 0 [PCH ]: HDA-Intel - HDA Intel PCH HDA Intel PCH at 0xdc428000 irq 295 1 [H ]: USB-Audio - Logitech G933 Gaming Wireless H Logitech Logitech G933 Gaming Wireless H at usb->0000:00:14.0-1, full speed
So the sound cards are recognized. However, audio is not played:
$ aplay /usr/share/sounds/alsa/Front_Center.wav ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Access denied aplay: main:722: audio open error: Connection refused
$ sudo aplay /usr/share/sounds/alsa/Front_Center.wav Home directory not accessible: Permission denied Home directory not accessible: Permission denied Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit >Little Endian, Rate 48000 Hz, Mono
The "groups" command does NOT show the audio group, but what I think is strange that it works most of the time (and often so after restarting, if there are problems) so I'd guess it's not the problem.
Where else could I look?
$ lspci -nnk | grep -A2 Audio 00:1f.3 Audio device : Intel Corporation Device [8086:9d71] (rev 21) Subsystem: Dell Device [1028:075b] Kernel driver in use: snd_hda_intel $ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: PCH [HDA Intel PCH], device 0: ALC3246 Analog [ALC3246 Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: H [Logitech G933 Gaming Wireless H], device 0: USB Audio [USB >Audio] Subdevices: 1/1 Subdevice #0: subdevice #0 $ pactl list short sinks Connection failure: Access denied