You didn't post the output of
lspci | grep audio (they are two different commands)

Seems to me that sound devices are properly recognized by PCLinuxOS.
But I see the chipset is ALC887. Guess this chipset is causing problems on many Linux users.
Can you completely uninstall pulseaudio (using task-pulseaudio-remove from Synaptic), reboot and try to run alsamixer again?
Before that, go to PCC -> System -> Users and check if the user is included in the "audio" group.