sudden iBook Shutdown

[blunderboy]

So, I just had a weird random shutdown about 20 minutes ago. I rebooted the machine twice and everything was working fine after that, but I checked Console to see if anything was wrong.

Console reported "05/03/2010 14:12:37 kernel ApplePMU:MU forced shutdown, cause = -127" and a little later, "Improper shutdown detected!" I don't know what's going on here, although I suspect that the PMU might be acting weird because the battery is dead. No kernel panics are showing up in the console log, and I didn't get the "Mac OS X recovered from an unexpected shutdown" message on reboot.

I'm hoping to God it's just the dead battery and not a failing logic board or something. I haven't seen any of the symptoms of that, though; as I said, I did two test reboots after the computer shut itself down and everything seems to be fine.

Specs: the computer is an iBook G4 1.2 ghz, early 2004 model. It's been in good working order except for a dead battery.

 

[jodelli]

If you are running on ac and the battery is dead (NFG, no longer charging) then a power interruption from the ac can trigger a 'PMU forced shutdown' message.

This is one possibility.

 

[blunderboy]

Makes sense to me. I don't know if there was a brief power outage or not, because I didn't have any electronics on but the computer and I wasn't using it when it shut down. I'm also wondering if I'd had it underpowered; I was using a 45w Apple power adapter from my old iBook G3 as opposed to the 65-watt 3rd party one that came with this computer when I bought it.

Everything seems OK right now—I went out and the computer was just asleep when I got back—but I'll post again if something happens.