Had gentoo linux for years. Original system had working sound, which gradually petered out (working in some apps and not others) until no sound at all.
Got a new system, a few months old, set it up according to the ALSA guilde (wiki.gentoo.org/wiki/ALSA) but no sound. Physically removed the speakers, plugged into laptop, works fine. Put back in desktop (linux) and no sound. linux # lsof /dev/snd/pcmC1D3p linux # speaker-test -t wav -c 2 speaker-test 1.0.27.2 Playback device is default Stream parameters are 48000Hz, S16_LE, 2 channels WAV file(s) Rate set to 48000Hz (requested 48000Hz) Buffer size range from 2048 to 8192 Period size range from 1024 to 1024 Using max buffer size 8192 Periods = 4 was set period_size = 1024 was set buffer_size = 8192 0 - Front Left 1 - Front Right -- I got the sound device from lsof | grep snd with a java app running which locks the sound device. Did the above with it shut down. alsamixer shows 2 cards, 1 HDMI, so I presume I got the right 1. The speaker cable is green so I plugged in the middle green hole (which also says "line out"). Also tried the other ones ("line in" and mic symbol). There are no other audio slots anywhere so I think is a software problem. alsamixer calls the card "HDA AIT SB:" chip "Realtek ALC887-VD" I have PCI/Intel HD Audio/Realtek enabled (plus many others in that group). I'm doing all this testing from root. I've tried everything I can think of, what next?