ALSA no sound

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