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imac g5 freezing, overheating?

post #1 of 14
12/6/07 at 8:48pm
Thread Starter 
Hey there.

I recently purchased an imac g5 (Original 17": 1.6Ghz, 768MB ram) for my mom. The computer has been running and performing great.

However, yesterday the imac began freezing. These are hard freezes, the mouse is not movable and keyboard completely unresponsive (ie. caps lock light won't even light up). A few moments after freezing, the fans go on full blast, and the only way to turn the computer off is by holding the power button.

I ran the hardware test disk that came with the computer, and everything passed fine.
I tried doing an archive reinstall of the OS, but the computer froze while "checking disk".

I took the back off of the imac, booted it up, and stressed the cpu a little, watching the 4 leds on the back (checking to see if the fourth led (overheat) would light up). After a while, the computer froze hard, but the overheat led did NOT light. Interestingly, this time some text displayed on the screen saying things like 'stack overflow' (kernel panic). This is the only time debugging text showed (while the back cover was off).

Does anybody have some suggestions for us how to remedy this? Considering the imac didn't freeze while running the hardware test (which runs with fans on full), I thought it might be a temp issue, any way to adjust the base fan speed on a ppc imac? Very peculiar, as for the temps seem to be as they always have (50-60C cpu) and the computer has been running great...

I appreciate any help! =)
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post #2 of 14
12/6/07 at 8:57pm
Sometimes dust can build up in the cooling ducts. Take it to a gas station, pay the 75c, and hit the slot on the back and the intake hole with some compressed air. A much better deal than what you get when you buy it in a can.

Otherwise, it's possible that one of the RAM chips is faulty or perhaps just not quite seated in its slot.
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post #3 of 14
12/6/07 at 9:07pm
Those machines, specifically the first-generation 1.6 and 1.8 GHz iMacs, are absolutely notorious for such problems. Chances are, you have a bad logic board. Luckily, there's a repair extension program for those, so AppleCare or not, those issues are covered for three years. However, the REP only covers the logic board when it yields video artifacts and tearing, etc., or shutdown/sleep related issues with the power supply. Tell a little white lie and say that it's doing at least the video problems, and feel free to exaggerate some "occasional, random shutdowns". Considering how much they messed up with those, they're usually really lenient. If they still deny it, bitch enough and you'll likely get a CS code, which is basically the golden ticket to Repairville.
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post #4 of 14
12/6/07 at 9:20pm
Thread Starter 
Thanks for the suggestions.

Splinemodel, I have tried cleaning all visible dust and re-seating the ram.

Karelia, I would like to learn more about this repair extension program, there are no apple stores here. The imac does not sleep well; if the imac is put to sleep, it immediately shuts down. How do I apply for the repair?
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post #5 of 14
12/6/07 at 9:27pm
Quote:
Originally Posted by Eleaf View Post

How do I apply for the repair?

1-800-275-2273.

They'll probably have you ship it in if there's no Apple stores nearby. They may refer you to an authorized third-party specialist in the area, if there is one. Coincidentally, I happen to work at one in northern Michigan.
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post #6 of 14
12/6/07 at 9:34pm
Thread Starter 
Karelia, ah. Yes, there is an "authorized apple retailer" here.

According to http://docs.info.apple.com/article.h...tnum=302181-en , the iMac I have fits within the W8435xxxxxx - W8522xxxxxx serial range.
I suppose we will have to contact them to see if they can do anything, yikes. My mom is pressed for time because she needs to have the computer for her accountant by next week.

Yarrrrgghhhh... I wish there was a way to control the fan speed, at least then the computer would probably be usable for longer...
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post #7 of 14
12/6/07 at 9:40pm
Quote:
Originally Posted by Eleaf View Post

Karelia, ah. Yes, there is an "authorized apple retailer" here.

According to http://docs.info.apple.com/article.h...tnum=302181-en , the iMac I have fits within the W8435xxxxxx - W8522xxxxxx serial range.
I suppose we will have to contact them to see if they can do anything, yikes. My mom is pressed for time because she needs to have the computer for her accountant by next week.

Yarrrrgghhhh... I wish there was a way to control the fan speed, at least then the computer would probably be usable for longer...

The heat has very little to do with it. Numerous iMac motherboards are simply defective. If it was heating up, the fans would spin faster to compensate. They go full blast after the hard lock, because the motherboard is programmed to do that, in the case that it loses contact with the fan-control software, as a safety measure.
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post #8 of 14
12/6/07 at 9:48pm
Thread Starter 
Ah, interesting.

Well I hope this computer is less than three years old. I'm not sure when the original owner purchased it, probably in 2004 (according to all the printed material) =/.

We will have to call the local apple specialist next week and see what they say.
I really appreciate your assistance and direction!
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post #9 of 14
12/6/07 at 10:00pm
Quote:
Originally Posted by Eleaf View Post

Ah, interesting.

Well I hope this computer is less than three years old. I'm not sure when the original owner purchased it, probably in 2004 (according to all the printed material)

If you give me the serial number, I will look up the approximate purchase date.
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post #10 of 14
12/6/07 at 10:07pm
Thread Starter 
Karelia, you are very helpful

The serial number for the iMac is W84453YPPP6
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post #11 of 14
12/6/07 at 10:13pm
Eh, it's what I do.

Looks like the approximate purchase date was 12/03/07. Just barely past three years. You've got a few options...

1) Take it into the Apple Specialist nearby. Often, they will take pity on your problem and apply for the repair as if you brought it to them before the 3rd. That gets it covered automatically.

2) Take it in, and see if they can help you get it covered anyway. Depending on who you get ahold of at Apple, they will push the repair through anyway, realizing that denying a repair because of a few days is being a total dick.

3) If you can obtain a sales receipt that includes the unit's serial number, and states that the machine is less that 3 years old, give that to the specialist. They can use that to change the original purchase date, bringing the machine within three years.

In any case, whatever you do, do it ASAP. I can't stress that enough. The longer you wait, the harder it will be to get it covered.
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post #12 of 14
12/9/08 at 6:50am
Hi,
I bought a 20" iMAC back in Nov 05 one of these first generation models. Up till June this year my computers worked fine and Ive been more than happy, however I have had that problem of the computer just switching off. So I took it to an Apple service provider in Liverpool (MCC as there wasnt an official Apple store at the time in Liverpool). They saw my comp fell within the serial range and fixed it for free. Great. This weekend I came back from London and switched the Mac on only for it to freeze up. Similar to all other posts below, no problem I thought as my comp had been fixed with no probs last time. However the new Apple Mac store in Liverpool have said that the 3yrs finished 5 weeks ago and as the power supply was fixed previously by MCC it isnt eligible for the free fix and just quoted me £74.75 for labour and £495 for the part!?!?!
There is no way I can afford this and despite quoting various forum posts staing this is a known problem with 1st gen iMacs they refuse to fix as they say it is not a power issue and the 3yrs are up.
I cant afford to fix this and cant afford a new comp so Im stuck, does anyone have any specific info I can quote to get this sorted or I am stuck now due to its age.
Even if I could afford the repair Im worried that this will happen again and again (due to the previous fix in July) therefore just throwing money away if I stay with my currecnt Mac...? Please advice needed desperately!
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post #13 of 14
12/9/08 at 7:40am
Sorry my serial numbers W85396UK it seems mine falls out of the serial range anyway...gutted! Again any advice will be greatfully recieved even if its to say no chance. Will teach me to buy a first generation one I spose...
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post #14 of 14
1/27/09 at 1:24pm
I just wanted to point out maybe a reinstall would be good because ive heard of a computer freezing alot because of a missing file.
Powerbook G4 12", 1.5ghz, 768mb, 60gb, 10.4.11
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Powerbook G4 12", 1.5ghz, 768mb, 60gb, 10.4.11
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