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Sudden shutdown

It started after the 10.4.7 update. When I rebooted after the update, My G5 would just shut down right away, like someone pulled the power cord. iTunes was a startup item and caused this. And did so later when I would start iTunes myself.

I threw out caches, reset the PMU, unplugged all devices/cables, reset PRAM, ran Disk Utility and TechTool Pro, deleted iTunes and related files, re-installed iTunes. Not sure what did the trick but the shutdowns were gone.

But they came back. A few times after starting iTunes and also a few times when surfing the web. So more rounds of unplugging, resetting, etc. and it would be fine again.
Today it happened again after starting iTunes, and unplugging, resetting, etc. would not help. Same thing on a second hard drive with pretty much a clean install of OS X. So I can't use iTunes anymore...

This is from the sytem log:
Aug 19 21:47:23 localhost kernel[0]: ApplePMU::PMU forced shutdown, cause = -122

I've seen more posts about the same problem, also at www.xlr8yourmac.com, and the same problem still happening after repair. Not sure if bringing it in for repair would help. The problem might be gone all of a sudden, who knows when it comes back, and it seems that nobody knows what the problem is so that would make it impossible to repair.

Or did I miss something? And I wonder what all people with the same problem did. Just living with the occasional shutdown now and then? I saw a much older post by sAik0, someone with the same Mac who had the same problem when starting iTunes and later wrote that iTunes wasn't the problem but that Topic has been archived and replies are not allowed...

My guess is that it's a problem with sound, iTunes talking to hardware. Or maybe QuickTime? (Because it happened a few times when surfing the web and maybe Safari needed QuickTime on some sites?) I'd like to hear from people with the same problem. And any idea what a good way would be to contact Apple about this? It looks like it's just faulty and Apple should fix this...

G5 dual 2.3 Ghz Mac OS X (10.4.7)

Posted on Aug 19, 2006 8:40 PM

112 replies

Nov 12, 2006 6:52 PM in response to Jeroen Pietersma1

Agreed. It's almost pointless contacting Apple - they run through the standard procedures already talked about here and other places like xlr8yourmac.

This is annoying - especially as Apple have not addressed this issue. Should we keep our fingers crossed and hope they are working on a fix? Or replace hardware in hope it may solve the problem?

In anycase - no doubt we're going to end up with corrupt files if our powermacs keep shutting down in the middle of work.

(ps - have a 2.3 tower and having the exact same problems since 10.4.7)

Nov 12, 2006 6:55 PM in response to Dan-o

Mine started sometime after I installed 10.4.8. I can' t be certain how long after but I may not have been running iTunes in the meantime and it's not run at startup. BUT, mine started after I installed Lightroom Beta 4 and tried to run a slideshow. As soon as I hit play, which launches iTunes to play the music for the slideshow, it shutdown. It would do this every time I pressed play in Lightroom Slideshow. Then it started happening randomly in other programs too, PhotoShop, Bridge, Safari, Daylite.

The PMU was reset and it worked for a day and a half before randomly shutting down again. This isn't the boot problem. I can boot ok and sometimes run for a few hours before I get a shutdown, other times it's 15-30 minutes. But once it starts, it's almost every 10 minutes or so it seems.

My G5 is a June 2004 model that I purchased in October of 2004.

Dan-o

Level 2

403 points

Nov 12, 2006 7:04 PM in response to mykguilbault

Maybe there are two distinct shutdown problems (sounds like)?

A) Computer kills power (shut down) during boot up process.

B) Computer kills power at random times during normal usage.

Sounds like iTunes and system version have an effect on B, but I'm not at all sure they have an effect on A. I've not experienced B at all. And until this morning, never experienced A, despite having used 10.4.7 and 10.4.8 almost since the day each was introduced.

Nov 12, 2006 7:16 PM in response to Dan-o

Well mine is definately version B. I updated to 10.4.7 & 4.8 a soon as they were available (can't remember when that was now - anyone know?), but didn't experience the problem until about 10 days ago when I started the Lightroom slideshow as I've already mentioned. Odd... but I seem to remember it worked ok in iPhoto (I was trying to get a proof presentation ready for a client and had to revert to iPhoto when I started having the shutdown problem in Lightroom), but since then, happens anywhere.

There are two shutdown problems, and so far, it doesn't look like Apple has acknowledged version B.

Nov 12, 2006 7:29 PM in response to Dan-o

Dan-o, maybe it' the same problem but maybe somethings else is causing it to happen. Did you try deleting caches?
Library/Caches
and
user/Library/Caches
I tried that a few times and it;s not going to solve the prolem, but the behaviour seems to be a little better when I do that after a shut down.... (Or maybe it's just my imagination, wish, or something)

Dan-o

Level 2

403 points

Nov 12, 2006 7:44 PM in response to Jeroen Pietersma1

I did the system cache purge earlier today with no luck.

More recent developments:

1. Whatever this problem on my machine is, it killed the friggin Hardware Test about 6 minutes into the thing. Boom. THe whole thing just shut down.. no errors or anything.

2. I went all the way back to a hardware restore (10.3.x) and it also is of no use.

Fearing the worst at this point as I've been over every possible permutation of system install, APS checks, hardware and software tests, etc. : (

Nov 13, 2006 5:07 AM in response to Dan-o

Has anyone had their power supply replaced? Does this solve the problem? I'd like to at least eliminate that as a possibility for the Random shutdown (as opposed to the boot-up shutdown). At this point I'm willing to pay for that if that's what's needed to be up and running reliably again.

Nov 13, 2006 5:45 AM in response to mykguilbault

Mike_Guilbault-

No, but my gut tells me these problems are related. Something along the lines of the power supply not having enough oomph to get things started, but what do I know?

Have you contacted Customer Service and had them open up a case number?

Firm yet polite. I believe that enough folks calling them was in part responsible for the original identification of the random shutdown problem. Enough people ring up Apple with an official complaint and it will have to be addressed.

Luck-

-DaddyPaycheck

Nov 13, 2006 6:10 AM in response to DaddyPaycheck

I'll do that today. One thing I did notice this morning. I have a startup item, iTunesHelper.app running. I know iTunes is a suspect, but what is iTunesHelper? I wouldn't have put it in my startup items list (simply because I don't know what it does). Any ideas? Could this have something to do with it?

Dan-o

Level 2

403 points

Nov 13, 2006 6:15 AM in response to mykguilbault

That's the startup item I was mentioning earlier that I always run without, but which is a default on most people's machines. That loads at login basically. What it does I'm not sure, but that could be part of the problem for those having intermittent shut-downs while using iTunes.

Nov 13, 2006 6:18 AM in response to mykguilbault

Mike_Guilbault-

Besides the obvious answer, I haven't a clue.

But I can tell you this-the current version of iTunes seems to put a far heavier burden on the resources of any of the G5 Macs that I have used it on. Especially in the reflective album art view.

If this is the case, then perhaps it (or other programs that I do not use) is pushing Macs to some kind of breaking point. My guess is that it is a hardware breaking point as opposed to a software thing.

Did I mention firm yet polite?

Luck-

-DaddyPaycheck

Nov 13, 2006 6:30 AM in response to Dan-o

So... I assume then it is safe to delete it from the startup items list? But does this fix the problem? I'll disable it this morning and see how things go.

Nov 13, 2006 7:03 AM in response to mykguilbault

It's safe to delete from the startup items list, but that dus not fix the problem (I think iTunes adds it when installed and/or when you use iTunes' help).
At http://www.xlr8yourmac.com/systems/DualCore_G5Shutdowns.html there are some reports about replacing power supply, also logic board, ram, video card...
About the power supply not having enough muscle: might be, but that would be related to the software of 10.4.7 and 10.4.8 - the latest iTunes works well here with 10.4.6...
I wrote a letter to Apple Customer Service, will mail it today... Might work better than a phone call?
And maybe this thread gets Apple's attention; it is getting quite some views

Nov 13, 2006 7:13 AM in response to Jeroen Pietersma1

I'm no technician, but is it possible that the upgrade to 4.7/4.8 has altered or tainted the BIOS? If it has, then no matter what version you 'go back' to, the BIOS would still be tainted.

Nov 13, 2006 7:15 AM in response to mykguilbault

I went back to 10.4.6 and no problems at all.
Well, one problem: Aperture wouldn't work, so I upgraded to 10.4.8 and the shut downs were back right away.

Sudden shutdown