Ahhh... the famous Pismo... a great notebook but many quirks;
MAIN QUIRK (made me bucks in the day) If the small internal CMOS battery (Not the main battery) goes stone dead... the Pismo will not boot and also appear stone dead (I used to buy them by the truck loads from companies and eBay that thought they had dead logic boards); at any rate simply replace the CMOS battery and hold the reset button (on the back) with a paperclip and they boot right up
Oh sorry back to you question... I have fixed the sound issue that you described by re-setting / zapping the P-RAM; hold command-Option-P-R (all 4 keys) when powering up and wait until it chimes and re-starts 3 times before releasing them; as I remember (and it's been a while); this would fix some sound issues; you can also try a fresh 9.2.2 install or replace or reseat the AC Power/sound board as it is a separate, inexpensive board that is NOT a part of the main logic/mother board
- Jerry