bizarre stumper: random iBook beeping


Okay, 500MHz dual-USB iBook (i.e. 2002-3 vintage iBook), fresh install of OS X 10.3.9. Here's the issue:

The computer beeps at random intervals, and --

- It makes the noise even if the speakers are set to Mute;
- It is not the System beep sound (it sounds like the Old OS 8/9 default System beep, in fact);
- It does this when only the Finder is running (no other apps, i.e. it's not some sound being made by Mail when checking for messages);
- In fact, it does this if I just leave the computer sitting there at the login window upon startup;
- I cannot seem to find the "guilty" process by looking at the Activity Monitor, or by perusing the system logs in Console.

I like to think of myself as pretty knowledgeable on these issues, but this one has me completely and utterly stumped.




Scratch & Sniff Committee
In some iBooks there was a hardware issue where the the hard-drive motors would interfere with the audio signal going to one of the speakers, so that on some occasions it would emit a very faint beeping sound. An authorised repairer should be able to re-position the cable inside so that it is properly shielded and this doesn't happen anymore. Don't try it yourself, though, as its pretty fiddly.