This is an extract that I think is relavent to my problem, can I have some advice on how to do this type of change.
"No Sound with Onboard Intel Sound Card
There may be an issue with two conflicting modules loaded, namely snd_intel8x0 and snd_intel8x0m. In this case, edit rc.conf and in the MODULES array blacklist the latter one so that it reads !snd_intel8x0m afterwards.
Muting the "External Amplifier" in alsamixer or amixer may also help. See the ALSA wiki.
With Intel Corporation 82801 I (ICH9 Family) HD Audio Controller on laptop, you may need to add this line to
/etc/modprobe.d/sound.conf
options snd-hda-intel model=laptop
or
options snd-hda-intel model=laptop enable=1 index=0
Otherwise, the pcspkr may not work, and only the headphone have sound. "