Does this sound symptom perform the same way when using external speakers
or headphone; or is it confined to just the built-in or internal speakers?
•About NVRAM and PRAM:
http://support.apple.com/kb/HT1379
Not sure how you could test to see if this is a hardware issue; except if you had
some other system (such as an external clone) to see if the software installation
were part of a problem. I'd have to totally guess at random, w/o substantiation.
Troubleshooting software vs hardware issues is helped if you have & use other
tools, since the primary installed system can only do so much. And an Apple
Hardware Test, or Disk Utility, either one may miss important failure clues.
Perhaps someone who may have experienced and resolved a similar issue
may see this and reply. Sadly, more of those who had these computers and
still visit the ASC discussions, don't read or reply to old Mac areas very often.
•Resetting PowerBook & iBook Power Management Unit (PMU)
http://support.apple.com/kb/HT1431
Had you tried to reset the Power Management Unit - PMU? Another thing that
may or may not be related, is the PRAM (NVRAM) reset. This is where you
hold down four keys on startup, and let it chime three times before you let the
four keys go, and then the computer would start normally. This may help.
Sadly, I don't really have an answer for this.
But do hope someone will have more ideas
of the kind you use to troubleshoot the PB.
Good luck & happy computing! 🙂
