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Can't boot OS X

I apologize that this is a complex post, but I want to give you all the steps I've already tried. I'm not yet ready to throw this machine away.


Hardware:

Power Mac G4 (QuickSilver 2002), 2 x 1GHz


History:

Computer was running Mac OS X without issues. One day, the computer would not fully boot. It starts to boot with the Apple graphic and spinning pinwheel, but after some time, displays the circle with a line through it.


*Tests Performed*:

• Attempted to boot to TechTool CD ... same problem.
• Attempted to boot to Network Boot Disk (Mac OS X) ... same problem.
• Attempted to boot to FireWire Disk (Mac OS X) ... same problem.
• Replaced all memory with known-good memory ... same problem.
• Disconnected all IDE/ATA cables and attempted to boot to network disk ... same.
• Found a similar machine's Apple Hardware Test CD. Booted to that and ran all tests ... PASSED WITHOUT ERROR.
• Booted from Mac OS 9 Installer WITHOUT PROBLEM
• Installed Mac OS 9 to hard drive WITHOUT PROBLEM
• Still booted from CD, opened System Preferences and selected Startup Disk ... computer froze and mouse would not move.
• Used option key to select boot drive. Selected OS 9 ... machine froze at "Welcome to Mac OS"
• Zapped PRAM ... same problems.
• Reset PMU ... same problems.
• Tested internal battery. It shows 2.7 volts (lower than spec), so replaced it with fresh battery (measuring 3.4 volts). Computer WILL NOT POWER ON!
• Removed battery ... computer returns to previous problem state.
• Installed original battery ... computer returns to previous problem state.


I'm eager to hear what other people think about these symptoms. Please provide ideas on how to troubleshoot/fix this problem.

iMac 27", Mac OS X (10.6.4)

Posted on Jul 10, 2010 12:38 PM

Reply
18 replies

Jul 10, 2010 2:35 PM in response to Carl Ketterling

Hi Carl, not complex at all! In fact, I don't think I've ever seen as complete, precise posting of what's the problem is or what's been done ever, congrats! 🙂

One thing you didn't list & may or may not help...

Does it boot into Open Firmware with CMD Option+of ?

http://docs.info.apple.com/article.html?artnum=42642

reset-nvram (press Enter)
set-defaults (press Enter)
reset-all (press Enter)

Does it Safe Boot from the HD, (holding Shift key down at bootup)?

Jul 10, 2010 3:16 PM in response to BDAqua

Well, it didn't boot, but the symptoms changed. Now, I get the Apple graphic and the pinwheel, and then I get the following text across the top of the screen:

System Failure: cpu=1; code=00000008 (Unaligned stack)

A quick search on this site makes me believe that one of the CPUs is going bad (or something related). Maybe the OS 9 CD doesn't use as much cache or doesn't use the 2nd CPU, and that's why it would boot. Is that what you think?

Carl

Jul 10, 2010 3:49 PM in response to Carl Ketterling

Suggest you repeat the Apple Hardware Test. Running the AHT in Loop Mode is an excellent troubleshooting step for finding intermittent hardware problems. It is especially useful when troubleshooting intermittent kernel panics. If Loop Mode is supported by the version of the Apple Hardware Test you are using, you run the Extended Test in Loop Mode by pressing Control-L before starting the test. Looping On should appear in the right window. Then click the Extended Test button.The test will run continuously until a problem is found. If a problem is found, the test will cease to loop, indicating the problem it found. If the test fails, be sure to write down the exact message associated with the failure.In some cases, RAM problems did not show up until nearly 40 loops, so give it a good run.

 Cheers, Tom 😉

User uploaded file

Jul 12, 2010 2:48 PM in response to Carl Ketterling

Well, I did try Tom's advice. The hardware test disk has been running for about 24 hours now (I stopped it on loop #121). Then reboot to the hard drive with Mac OS X installed, and the failure returns.

A bit more information, though. While it boots to a Mac OS 9 Installer CD and is able to install Mac OS 9, it can't boot to the Mac OS 9 hard drive that it installed.

Having a computer that almost works is much more frustrating than one that just stops working!!

Carl

Jul 24, 2010 8:19 AM in response to BDAqua

First, my apologies for the delay in getting back to this problem.

I wasn't sure where you were headed with this question, but I opened the system to look at the drives. OS 9 was the slave disk. I took out the OS X drive and jumpered the the OS 9 drive as master/single.

Now, I can boot OS 9 and get through the setup assistant.

What do you think was causing OS 9 not to boot before?

Does this lead to a solution for OS X, or am I stuck with an OS 9 ONLY machine?

Carl

Jul 24, 2010 8:31 AM in response to Carl Ketterling

I guess I spoke too soon.

I shut down the system and was going to wait for your reply, but I reread the thread and thought I should try using Power Fractal. When I tried to reboot the Mac, it gets to the "Welcome to Mac OS" screen and hangs.

Unless you have any other suggestions, I'll assume it's a heat-related problem with the processor cards (based on previous reading) and consider the unit trash.

Thanks,
Carl

Jul 24, 2010 10:07 AM in response to Carl Ketterling

" Unless you have any other suggestions, I'll assume it's a heat-related problem with the processor cards (based on previous reading) and consider the unit trash."

If you narrow it down to a processor issue, replacing the processor with a comparable used one or a faster third-party one is always an option. Many Forum regulars have upgraded their processor cards just for the speed/performance boost, and not because the original failed. You could check eBay for a used one or Other World Computing for third-party processor, like this one. If you think it's better to retire the computer than invest any $$ in it, it does have some value for the remaining working parts in it.

Can't boot OS X

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