imac only boots in safe mode, power's off otherwise

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imac only boots in safe mode, power's off otherwise

Hi all,

I've searched these forums but can't quite see anything exactly the same as the problem I'm having.
I haven't installed any new programs or really done much with the g5 apart from mail/surf for the last few months, it's usually on 24/7 however.
Turned it off overnight the other day and when I switched on in the morning it starts to boot but as soon as it seems to get to the point where the desktop would display (after the spinning cirle) I get some rubbish on the screen (imagine you've set the resolution incorrectly on a pc, looks a bit like that) - it then just shuts down.
Booting up in safe mode works fine, after I did this I went into the disk utility and checked permissions, it did find a couple of problems so once I fixed them I rebooted normally. Came up fine. However this morning when I tried the same thing once again it won't boot up, only in safe mode! Scratching my head a bit, anyone seen this or got any suggestions please?

Many thanks,

Matt

iMAC G5 Mac OS X (10.4.8)

Posted on Mar 2, 2007 1:03 AM

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Answer 1

Mar 2, 2007 4:21 AM in response to Biondi

Biondi-

Check and see if you are covered by one of these repair extension programs.

It sounds as though you are having power supply and/or logic board issues.

Luck-

-DaddyPaycheck

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Answer 2

Biondi Author

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Mar 2, 2007 4:49 AM in response to DaddyPaycheck

Hi DaddyPaycheck,

Thanks for responding - I don't believe it's the same problem however, the fact is it boots up every time (and stays up) in safe mode, it won't boot at all otherwise.

cheers,

Matt

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Answer 3

Mar 2, 2007 9:43 AM in response to Biondi

Biondi-

Have you tried it with all of your peripherals detached?

If it falls under the covered range you may still want to give Apple a call. Power supply issue manifest themselves in many ways.

Luck-

-DaddyPaycheck

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Answer 4

MGW

Level 7

27,041 points

Mar 2, 2007 10:16 AM in response to Biondi

You might want to boot from your install disk and repair permissions from there, also, try resetting your SMU and your PRAM. See if any of that helps,

Miriam

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Answer 5

Biondi Author

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Mar 3, 2007 9:32 AM in response to Biondi

Many thanks for the replies!

An update, once I boot up from safe-mode I can restart the mac (via the menu) and it restarts into normal mode fine.. However as soon as I shutdown and try and restart via the power button I get the same issue.. Very odd.

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Answer 6

blankreg

Level 1

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May 11, 2007 7:23 AM in response to Biondi

Hi Matt,

I have what sounds to be the same problem with my iMac G5 (20", 2ghz). I was hoping you had any additional information since your last post.

I have gone through 2 motherboard and 2 power supply replacements (the most recent one taking place this past weekend under the extended warranty program). The "freezing" problem didn't happen until approximately 8 months after the first mobo/ps replacement. Like you, I discovered booting in Safe Mode allows me to use the machine and as a result was able to salvage my data.

I was hoping the fixes last weekend would take care of the problem, but sure enough the problem returned immediately.

Oddly enough when I picked up the machine at the Apple store they had disabled Quartz Extreme. So when I sat at the Genius bar and approved the work, the computer ran fine. I re-enable Quartz Extreme when I returned home and that's when the problem started again.

Here is a link I found with instructions to disable Quartz Extreme from Terminal:

http://felipecruz.com/g5-freeze-ups-problem.php

(instructions are located at the bottom of the page.)

I'm not in front of my iMac right now so I can't verify this isolates the problem, but you might want to try it out yourself.

thanks
josh

iMac C2D 20" Mac OS X (10.4.9)

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Answer 7

MGW

Level 7

27,041 points

May 11, 2007 9:11 AM in response to Biondi

You may have a corrupted preference, check by using Preferential Treatment and see what it comes up with.

Miriam

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