Sudden shutdown

Hi, I've been a bit busy but got another letter from Apple, although I was asking if they could set up a free diagnosis at an Apple Store, I got the same answer again: no written correspondence about tech issues... But the recommendation to call tech support and ask for a Product Specialist. Not sure if I can find the time in the coming few weeks, although I could use Apple's help now: the trick of double clicking a music file in the iTunes library to start iTunes without the shutdown, stopped working... Starting the iTunes app would always result in the shutdown, and that trick worked for a month but now that will also trigger the shutdown every time... I'll be back a little later.

Hi all,
A little step further and some stupid stuff, the kind of little bad luck that happens to me more often. Plus some sort of a solution for the shut downs...
I had enough of my half working Mac (well... half working... it's actually working pretty good but iTunes causing these shut downs makes it feel like it's only half working) so I called tech support and paid the $50, went through some basic things and after a while the only thing that was left before I could move on to a Product Specialist, was Erase and Install. Good thing I have a good backup. I didn't expect this to work, since I downgraded to 10.4.6 before which doesn't have the shut downs, and also I have a second internal hard drive that started with a clean install of Tiger without any additional software but once it got to 10.4.7 it would also get the shut downs when I was starting up from that disk.
Anyway. After the Erase and Install I'm at 10.4 and I can start iTunes without a problem, I do all the updates that show up in Software Update, except for the 10.4.8 combined updates. After all these updates (including the newest iTunes) everything is fine. Then I go up to 10.4.8, I start iTunes and yes, my Mac shuts down.
Then I get to talk to a product specialist and we check if it's the RAM, I have to take out the RAM I added and leave the original RAM in; two 256 modules and then there's a misunderstanding about upper/lower and he doesn't mention matched pairs, something I forgot about, we switch around some RAM, I'm using just one bank, no matched pairs and then, of course, the Mac doesn't start. I head over to the Apple Store, the guy at the Genius Bar tells me they can't do a diagnosis and they'll have to replace the logic board and the power supply and possibly the processor and RAM. That's roughly $1500. So I go back and all of a sudden I remember the matched pairs... So that was a silly situation.
I was back on the phone today and now talked to a product expert who sent me a little app to capture some data and mail that and send info from the System Profiler app. The expert would send it to an engineer who will look into the issue and it's probably going to take 5 business days before I hear back. The Product Expert told me it's probably a hardware issue and that iTunes was asking for a lot of processing power... But I use apps that ask a lot more processing power and I still think it's at least half a software issue: the problem does not exist under 10.4.6 and iTunes is doing something that the system or the hardware doesn't like.
I was reading some more stories on the web about a chirp in the G5, which also happens with my G5 when I start iTunes. I read a tip about that, which also turns out to be half a solution for the shut down problem: set the Processor Performance in the system preferences (Energy Saver) to Reduced and the chirp will not be as loud. Turns out I can also start iTunes without my Mac shutting down, with that setting! But it's not a real solution, my Mac should just work and I looked at some benchmarks and with Reduced settings my 2.3 looks more like a 1.6 or maybe a 1.8 MHz Mac...
Sorry for the long post, long stories are easier to write 🙂

G5 dual 2.3 Ghz Mac OS X (10.4.8)

by the way, it seemed like the product experts weren't aware of the shut down issue, while there are quite some people with the shut downs, in this forum, and I've read a lot of other stories on site as xlr8yourmac and macintouch, and maybe that's because we were all just here talking about it... If Apple gets more of these shut down cases, the engineers will know something is really wrong and it's not just one machine... so if you can miss 50 bucks and some time, please help.

Hi all,
So the issue went to an engineer and after a few business days I got a call back: the rep asked me to play a DVD with DVD Player, use iMovie and Garageband, and she said that it was likely that using those apps would also trigger the shutdown. I played around with those apps (with Processor Performance at Automatic and Highest) and all went well. Then I started iTunes and as usual, it triggered the shutdown. I sent this to Apple and today the rep called back:
The engineer checked the logs and didn't see any report about iTunes triggering the shutdown. They found the log entry "PMU forced shutdown, cause = -122".
Um, that was no news; I already mentioned that several times when I was on the phone for hours to get this started.
The rep todl me they think it's an issue with the power supply, that iTunes draws more power, causing the shutdown. Why this only happens under 10.4.7 and 10.4.8 and not when running 10.4.6? That's because 10.4.8 "runs a little different" and "interacts different with the hardware then before", the rep told me and concluded it's a hardware issue and she suggested I have my G5 serviced and have the power supply replaced "and see if that works" because they "don't know if it causes the shutdowns."
I don't feel like paying a lot of money for a new power supply, especially not when Apple can't guarantee that it will fix the issue while Apple admits something has changed in the OS... But it looks like this is where it ends and that my G5 has to be on reduced performance when I want to use iTunes... basically making it a less powerfull G5...
I said there are quite a few people out there writing about the same problem on the net. The reply: "People write a lot of things on the net." She also said they would "look into other things" when they receive more reports.
So to get your report to an engineer might help... unless Apple keeps telling it's a hardware issue no matter what...
While I was writing this, I was thinking a little more about the remark about 10.4.8 interacting differently, that's basically saying it is something in 10.4.8... It might be hardware related, but it's caused by OS X... Or in other words: Apple sold G5 Macs that aren't ready for the 10.4.8... And then "look into other things"" when they get more reports... Doesn't that translate into: we're not getting to the bottom of this because of one report? So I might not have been too sharp when I got the call but I was in the middle of some work — already left a voicemail for one last chat with the rep.
So anyway, if you have these shutdowns with the "PMU forced shutdown, cause = -122" error... more reports might help, and probably the only way to get your report to an engineer is paying the $50 fee for tech support and it will cost some time...
Maybe it's also a good idea to compare serial numbers of the Macs, if we're all in the same range, that should mean something. My Mac: YM5141EHRU3
You can find the serial number in the System Profiler, or choose About This Mac in the Apple Menu and click twice on the spot where you see "Version 10.4.x"
Thanks,
Jeroen

Update: already got called back before I posted this: now the rep told me they looked at it "thoroughly" and was pressing the hardware issue a bit more, the OS changed but I "need a new power supply", no clear answer to my question: what would happen if I get the power supply replaced and I still have the shutdowns... And the other people with the same issue? Then there would be thousands and thousands of people with shutdowns, the rep said.
Well, it could be just a number of G5's within a certain serial range... I mean, look at the Power Mac G5 Repair Extension Programme for Power Supply Issues at http://www.apple.com/uk/support/powermac/powersupply/repairextension/ Anyway, the rep said other people might have a similar hardware issue. Well, could be, but maybe the power supply is fine, just not for 10.4.8... But there's nothing she could do or they have to get more reports. They will keep the issue on file.

G5 dual 2.3 Ghz Mac OS X (10.4.8)

Hi Ade,
When did you upgrade to 10.4.7? What was your Mac doing when the shutdown occurred?
The Mac handles an occasional shutdown pretty good but a few more might do damage and it won't hurt to run Disk Utility/DiskWarrior/TechTool after a shutdown or two...
My Mac runs with reduced processor performance (sys prefs>energy saver>options) for a few weeks now without a shutdown... That's the only way I can start iTunes without a shutdown.

G5 dual 2.3 Ghz Mac OS X (10.4.8)