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How to repair my iMac G5

iMac G5 17 A1058 start to die plus display trouble


My Imac was starting to do strange things on the screen, or sometimes was going full grey. And I had to restart manually?

I tought it was the Nividia graphic card.

I did open all, cleaned up old thermical paste and made a new one. Also made deep clean of ventilators.

Then reassemble the computer who turn on and work.

But problem is getting worst.

Sometimes not even time to wait for the overall start.

Already bloqued, or impossible to do anything.

Still some trouble spotting on the display.

But display stay stable and computer isn't running anymore.

I did check the 3 ventialtors, they work.

But the cover of the "big stuff" aluminum color with the big G5 logo is getting really hot and very quick.

Does any body know or have any idea ?

Thank's for all.


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On top, I did check the lite led on the motherboard.

n° 1 , 2 and 3 are OK. n°4 doesn't light up.

Last : capacitors looks all good condition (no leak, not swollen)


Here I add : The heatsink with big G5 logo is getting hot and quick (just in 3 or 5 minuts)

heatsink's fan does work (maybe not fast enough ?).

I did clean up the 2 entrances of the heatsink (was some dust) as well as it's fan.

The heastsink does get a lot hoter compare to the hard disk.

But lite led n°4 still keep off.


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Check this out.

Did you try a clean install of OS X? Otherwise it seems to be something very unpleasant. Maybe reset SMU.

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Hi Senthor, thank's for that.

I did already reset SMU and Pram. Doesn't work.

And leds controls are telling : all is Ok.

I can't re install OS X, neither do Hard Ware Test. My driver is out of order since years. I can't play any CD in.


Do you still have your OS X installation disk? Then you could reinstall using this method.


And what do you mean with "My driver is out of order"?

Is you ODD defective?


Senthor, I've checked your link.Thank's again. Does look diffcult for me, and I'm not sure to get one spare DVD player with the right USB connectors ?

I will study it, but not sure I'm capable to do this procedure ?

Theremore, procedure looks quite long.

Thsi imac is out of control 2 to 3 minuts after starting it. Sometimes after starting it, it does run well for only 30 seconds, than I have to turn off manually.

Yes I do have my original OSX CDs.

The combo CD/DVD player installed into this imac is out of order.

I did opened it, cleaned the optical lens. Don't work.

It takes Cd, turn them, try to read, but finally nothing, then CD goes out automatically.


Then there's a far more easy solution. You can easily replace the Combodrive, ifixit sells it for $89,95 but that's pretty much. You can get one from ebay for $20,29. If you already managed to clean you defective drive, installing a new one shouldn't be a problem. Then you can just install OS X the normal way. Or run a Hardware Test first.


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To check out your video card, hook it up to an external display and see if you get the same thing.

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I do have an external display to do the test.

But I don't find to buy the right adapter to plug the Imac with VGA or mini VGA extension to connect the external display.

This Imac 17" year 2005 isn't loaded with mini Dvi plug, netheir mini Display Port. It drives me crazy.

Onto this Imac it looks to be the same plug as the later SunFlower Imac does have ?

Does any body know the name this plug ?

I will buy as well new used combo CD/DVD to do Hard Test and Software test.

It will take some time.

I'm french, sorry for all my writting mistakes !!!


This is what you're looking for. It uses Mini-VGA.


Christian, this sounds like CPU problem.. It's the big chip under your silver g5 heat sink that you say is getting hotter... Doing mayers test should show this. If so you need a reball/reflow. Are you in France??


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Here I am.

New used combo installed and does work.

The computer does only start on Safe Mode.

Actualli is Installed with macOs system is 10.4.11

I do only have original CD OS 10.2

With this OS 10.2 CD It doesn't boot on Hardware test.

when I try to boot.

I can read on screen : "Invalid memory access at SRR0 and SRR1"

But trying the Hardware test (mac-boot + return) nothing happen.

I've tried to install OS 10.2. Unfortunatly after restart for new installation.

The screen is showing one black rectangle in middle. And nothing else happend.

I that correct to try to install OS 10.2 instead of actual 10.4.11 ?

Or better to try to install OS 10.5 or 10.6 ( I have CD of thoses).

I'm stuck !!!

please any advice.

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Did your machine fully work in Safe Mode?

If yes, that's wonderful, because then you only have software issues.

Was the 10.2 CD the CD that came with your iMac? Or did it ship with another computer? If it did ship with another computer, it can't work.

Same for the 10.5 DVD. Is that a retail one or OEM? If it is a retail DVD that did not ship with another computer you can install 10.5 Leopard. Leopard is the last OS version to support PowerPC Macs. See system requirements.


Senthor, thank you for the link, but i was redirected to another uncorrect adaptator.

Yes you're right form now I know it's : mini-vga port to Vga.

I asked one Ebay Us seller and waiting for response if he's selling the correct one ?

I did order new used combo. Will get it next week and proceed test.

My orginals Cd Hard Ware test and software are OS 10.2 and my system is running OS 10.4. something. Is that a problem ?

Thank's Pollytintop, when I did the new thermical paste onto the CPU.

I didn't checked well enough the CPU's balling. But they were looking Ok.

Yes I'm in France

Also big thank's to Mayer for your contribution, I will follow these recommandation.

I hope to solve somethings by next week or so.

You all are beeing very kind.


Got the new combo to be installed today.

But from now, with new or old broken combo.

Imac doesn't want to start any more: dark grey screen with => you must restart your computer, hold down the power button...

Led lites n° 1 2 3 on mother board are ok.

Does anybody have any idea ?



Senthor, thank's for you last comment.

Imac does start again in safe mode.

I do always one Kernel Panic if I start normally..

I finally found my OS 10.4 going with this Imac.

It isn't OEM.

It's a copy ("craqued"). Does work.

I cant Start with the CD. Does run starting pressing key C.

Does run starting pressing Alt.

And found in the utilites : SOS disk. Does work Also.

I made a check wih SOS.

Also available on the CD : Xcode and loads of files.

I didn't yet Re installed the 0S10.4. Will be first time ever for me.

"I'm scared to do stupid things or loose something"

I can't find any Hard Ware Test on that CD.

I've looking all around on the CD or event starting with Alt and check the menus. Can't find.


I'm quite stuck



That's wonderful, so you hardware is okay.

Hardware testing software is included in OEM discs only, so that's okay.

As for reinstalling OS X:

Do you have any sensitive data on your Mac? Do you need the files that are on it?

If yes: Do you have another empty (or only unneeded files on it) hard disc that you can install in the iMac? If yes, do so, then proceed. Otherwise, you can choose to archive and install.

If there are no files on the installed drive: do this.


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video graphics and boot issues there are plenty of YouTube guides... Let's face it you've nothing to lose!

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christian will be eternally grateful.
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