My iMac(early 2008) video display glitches, hard freezes, help!

D

domajean

macrumors newbie
Hello,

I know this is a long thread, I apologize for that but this is a really urgent situation and I don't have much time to solve it. Thanks for your futur help and your time.

I'm a video game sound designer and I use a lot my iMac for audio duties. This iMac(24 inch early 2008) running OSX 10.5 is a little more than 2 years old with an upgrade of 4 gig of ram I succesfully did 3 months ago. My apple care has ended.

Not too long ago, I have experienced little slowdowns and freezes. I solved most of this issue by cleaning the files on the hard drive.

Today, it was the 3rd day the iMac was running with no stop. I know, it's stupid from my part to have let this happen.

While watching the E3 Nintendo press conference, all in the sudden the screen went completely white , no more sound. The only sound I hurd, was the hard drive...it was like spinning in the wind, with a little ''chick, chick,chick'' sound.

I closed the machine. I opened it again 10 minute laters. The start seemed ok. I just did a get info on the HD to see how much space free there was and Boom! Big video glitches on the get info window and a complete freeze of the desktop. I closed the iMac for 1 hour, opened it again...and unplugged all the usb wires beside the keyboard....opened an audio software to see if it was capable of running any software...all seemed good...opened a song with itune...and there we go again! Big video bleeding everywhere, even worse than before with weird red lines all over the screen. At this point, I knew I had to do an up-to-date backup of my work before it goes more bad.

Wow, now I'm in big troubles. It is not all dark, since I succeeded to export all my important work on my classic 80gig ipod(I don't have an external hard drive). But now I'm searching the forums and I'm trying to understand all the possibilities of this problem.

At first, I was praticly ready to replace the hard drive in my iMac by following the different steps I saw on youtube...but after more deep net surfing I found that maybe the video card or the logic board was the cause of my problem.

I have a lot of softwares and files that I want to save, so I thought about buying a SATA hard drive adapter:

http://eshop.macsales.com/item/Newer Technology/U2NV2SPATA/

And use my old PC hard drive to back up all my OS. That said, I fear the possibility of cloning corrupted files...?

The last time I opened the iMac, I wanted to show to my roomate the problem, and no issue appeared beside a little video glitch after opening itunes, firefox and neo office one after an other...but the iMac kind of fixed himself and after that no glitches were showing...the processus were a little slow, thought. After that, I shutted down the iMac.

I still think it's an hard drive issue, but it could be so many things... I don't have a lot of money, for now, to spend on this problem. I don't want to send my iMac to Apple or anything and I want to be 100% sure of what is causing the issue so I can replace it myself without spending too much money.

If anybody can help me with this, I would be more than grateful!

Thank you for your time and consideration,

Dominic
 
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if you got the optional nvidia geforce 8800 in your 24" it definitely is the GPU , if you got the basic GPU inside then its the harddrive
 
Hi MacHamster,

Thanks for your fast answer! I have the basic GPU.

That said, could you explain why in that case it would be the hard drive and not the video card.

And if I backup all my OS and files on an external hardrive, does it has risk of duplicating the corrupted files(if there is any)?

Thanks a lot!

Dominic
 
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no i think if you got the the ati gpu and the ati is near bulletproof , just did want to eliminate the nvidia as source of the problem
as you did not mention if the temps are alright or if your fans kick in big times after a while
so first things first , you need to open the iMac definitely , so do it now and clean it inside , you will be surprised or shocked about the amount of dust inside , especially in between the fins of the GPU and cpu heatsink and on the fans , once cleaned and closed again , run the apple hardware test the extended version , that should find something
i doubt corrupt files are responsible , but you can always repair permissions (could cause problems too if the permissions are not correct )
replacing the harddrive after 4 years is a good idea anyway and they are not expensive really and your backup should be ok as you should be able to go back to the day before the issue started ;) if not clean install and only get the files you need of the backup (eg. dokuments ,photos ,music , films and such)
 
Hello MacHamster,

Thanks again for your fast answer. I will do the cleaning, replace the hard drive, and come back with the results.

Kind regards,

Dominic
 
It wasn't the hard drive :S

Hello,

After a long wait, I finally got my new Hard drive.

A Seagate Baracuda LP 2 TB...a nice update for my previous 500 GB western digital.

I carefully cleaned the Imac, installed the new hard drive. All went fine.

When I started the first time the Imac all was good...until one little glitch appear on the screen....but suddently, it disapeared....and I was able to continue the OSX installation, with some worries floating in my head.

''Ok, maybe it is just because it's a new hard drive''...this is what I was saying to myself to gain some confidence.

The installation is finished. I have to click continue, but, sadly, I see a little glitch...a little white dot on the blue loading line. I click Continue and the multicolor circle appear...Waiting...waiting...nothing.

I shut down the Mac. Open it again, it's loading on the white screen and....yea you guess it, it freezes.

I shut down again, open it again, and....o wow, the Welcome video appears...I'm an happy fella....praticly celebrating my mac revival....but during the video....something happened :mad:

That something is not good looking:



Well, the good news are that the imac is clean and updated with a new hard drive...

What do I do? :(

Dominic
 
After some research I found that this is maybe due to the graphic card who overheated.

It make sense because it was an hot day and my mac was on for 3 days in a row with some little brakes between, but not enough.

I finally got to the desktop, tried smcfans control and glitches appeared after a little while.

According to the other forums it is praticly impossible to change the graphic card or the mother board.

If anybody have a solution or anything...

Thanks.

Dominic
 
the graphics card on the 24" iMac can be changed
not a easy job as it means taking the iMac apart nearly to the bare shell as you need to remove the logic board complete and be very patient dont force things and make notes( better photos) where all the little screws go the whole process will take you a couple hours , but going to apple to get it done is not a option if you are out of warranty as a new refurbished one cost not much more then the repair bill
 
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Send a well thought out and well worded email to Apple customer support....tell them the issue, tell them in doing your research on it this is a common issue - which seems to be an actual defective component in your mind, and that you'd like them to fix it - free - just as a car mfgr would on an out of warranty fix for a known defect found after some time period.
 
domajean said:
Hi MacHamster,

I did a mistake by saying it was the basic ATI GPU.

I checked my imac specs and I have the Nvidia 8800 GS.

On the other forums, they say this card is doomed. Even if I replace it with a new one....the new one will defect after a while...

I don't know what to do...here's my research with the results:

http://www.mac-forums.com/forums/ap...video-display-glitches-hard-freezes-help.html
Click to expand...

yes that is true the nvidia will fail as often as it can be raplaced, in some cases the replacement nvidia did not last 15 minutes , but good news it can be replaced with the standard ati card ,its on a mxm socket ok its not as powerful but far from a bad card and much more reliable and that card is available somewhere
so get the standard ati and bin the nvidia
 
Hi fhall,

I contacted apple customer technical support this morning and they gave me these linksto reinitialise the PRAM and VRAM:

http://support.apple.com/kb/HT1379?viewlocale=en_US

Reset the SMC:

http://support.apple.com/kb/HT3964?viewlocale=en_US

Both didn't work.

They said if it didn't work, go to the Apple Store and explain the situation. With that the CS lady wrote notes on my account so they can view that I already contacted them.

I have to mention something odd...It will make 2 times in a row that the freeze come up when the GPU diode reach 49 Celcius degree...coincidence?

I'm going to the Apple Store and coming back with the news.

Dominic
 
Hi MacHamster,

Ok, I will do it, but first I want to know what Apple have to say so I will go to the app store and if they can't do anything I will change the video card by myself...

But I am wondering if there is any tutorial for this because it seems a little more complicated than the Hard drive lol.

Dominic
 
I just measured again the tempratures...

For the third time in a row, the artifacts and freeze start to appear when the GPU diode reach 49 Celcius degree.

Not a coincidence anymore...but why...? My fans seem to work properly...

That said, SMC fan control doesn't seem to work properly...I don't hear much difference even if I put the minimum speed of the fans at maximum...

When I save a new preset I can't even move the minimum speed meters.

Any idea?

Dominic
 
here the explanation of the problem on the 8800


The reason for the high failure rate was because of improper selection of the underfill material for the chip. Underfill materials are a type of glue that keeps the silicon die firmly attached to the packaging material, which is where the connection to the actual pins takes place. On the affected chips, the working temperature of the underfill material was too low for the task and allowed the chip to move slightly if temperature was raised above a certain level, weakening the solder joints by which the die is attached. This eventually leads to a catastrophic failure, although the way the chip fails is quite random.


NVIDIA CEO Jen-Hsun Huang and CFO Marvin Burkett were involved in a lawsuit filed on September 9, 2008 alleging that their knowledge of the flaw, and their intent to hide it, resulted in NVIDIA losing 31% on the stock markets.

so it is indeed a known problem and apple should replace the cards as is indeed a manufacturing problem
but apple always did replace them with the same tye of card under apple care ....result is often a failing card again
but there was a thread couple month ago about someone who tried to get it replaced with a ati card , maybe he knows more and if it was replaced with a ati card
 
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Hi MacHamster,

To begin with, I just want to thank you a lot for your follow up on my thread...really appreciated.

So I went to the Apple Store, the Genius guy said that considering the end of my Apple Care, he couldn't do anything. I explained the situation and told him I had proofs of what I was talking about. I explained that I need to have the ati card and he kept saying that apple only replace the card by the same card...yea great.

He gave me a business card from an apple certified shop and he said that they can maybe fix my computer. I called and they said they can do it for 200 to 300$...ouch.

I'm really interested by the thread you mentionned in your previous post, do you have any keywords so I can find it and check that out?

Dominic
 
Hello,

Just a quick update on my status:

So since nobody seems to sell the Ati Radeon 2600 HD pro video card anywhere on the internet for a decent price, I contacted a company named Dalailamac who is situated in Montreal.

They said they would replace the Nvidia by the Ati for around 400$(300$ for the videocard and 75$ for the work)

I will come back soon with the conclusion.

Dominic
 
Dude, that's waay too much money for that piece of hardware!

What's the price of a new iMac in your area?
 
You're right...after reading your post I had a talk with my roomate who works at Future Shop said that it would be around 80$ per month with a payment plan without interest.

For 5 month x 80 = 400 ... instead of spending 400$ for downgrading on an old imac I would have a brand new one...

Thanks for your input it opened my eyes...

Dominic
 
Hi everyone,

Here is the final update for that story:

Finally I decided to repair my iMac, because I like my iMac and it responds to my needs...So it cost me a total of 450$ to replace the Nvidia 8800 GS by the Ati 2600 HD Pro.

Not cheap, but now my iMac is alive again, 1 month later, with a new 2tb hard drive, and all cleaned up. Thanks to everybody who helped me out with this situation, shout out to MacHamster, thx a lot for your input buddy.

I have to go make some music,

Dominic
 
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