5.3.1 audio does not work on Asus laptop

[Cynthia Fu]

I installed 5.3.1 on my Asus laptop. But ALSA does not work on neither ROM version nor hard drive version. I execute 'lsmod|grep snd' shows:
snd_atiixp 24332 0
snd_atiixp_modem 20360 0
snd_ac97_codec 103716 2 snd_atiixp,snd_atiixp_modem
ac97_bus 6144 1 snd_ac97_codec

When i tried to manually 'modprobe snd_pcm_oss', I received 'FATAL: snd_pcm_oss not found'. When system starts up, console displays:
ALSA device list:
No soundcards found.

I tried other variation ie: 5.1, windows; audio works fine. What should i do to fix 5.3.1 audio problem?