Sound on and off randomly and inconsistently

[semin]

Long time folks -

Haven't used PCBSD for awhile (mainly due to my 8 years old laptop not being capable of any hard work anymore since my last PBI build work), and good to see that 9.0 has been released.

I have recently installed PCBSD 9.0-RELEASE (64bit) in a new desktop computer with the following specs:

- CPU: AMD Phenom II X6 1090T
- RAM: Transcend 16GB DDR3-1333 Memory
- HD: West Digital 1000GB SATA3
- DVD Writer: LG SATA 22x Speed Optical DVD Writer
- Video card: Asus NVIDIA gt440
- Motherboard: Asus M5A97

The audio did not work with this machine as this motherboard has an onboard audio from Realtek ALC887 which, in accordance with FreeBSD 9.0-RELEASE Hardware Notes, is not supported by FreeBSD9.0-RELEASE. So I just got another pci audio card with CMI8738-SX chipset from an online shop. From the same Hardware Notes list the driver snd_cmi(4) supports this card. In case there is any conflict between the onboard Realtek ALC887 chipset and the extertnal CMI8738 chipset, I turned off the onboard audio chipset from BIOS.

However I noted that for unknown reason the audio is not always working. Sometimes there is audio/sound when watching youtube in Opera browser, whereas next time when restart the computer all sounds are gone even though no settings are changed. And then restart the machine next day it works again. Sometimes when I start the machine there is no sound at all but then when I shutdown down the machine at the end of day the KDE makes the shutdown sound effect, which means the sound is back before I turn everything off for no reason.

I mainly test with youtube on Opera browser but beside this I have also tried mp3 from BSDTalk and also the sound effect when using Pidgin. When there is no sound from youtube there is also no sound in other situations as well.

I have saved two dmesg files to make comparison - one when the sound is working and the other one when no sound is available (please see attached demsg files). However I cannot see any difference between the two dmesg files in regard to the inconsistent sound issue.

I am not really sure whether or not it's the hardware's problem - maybe I should go get another reputable sound card like SoundBlaster Audigy2 ZS and try it out, but before this please could someone have a look into this and give some thought what is going on here?

Regards,
Sam