A Fairfax, Virginia customer recently had an iMac 24″ Intel Core 2 Duo 2.16 GHz (the two year old white acrylic plastic model) that had a malfunctioning video card (random lines, ghost windows, static). Otherwise it worked great, so we decided to fix it.
Bad Video Card
Because the iMac was not under AppleCare warranty, we decided not to have Apple fix it for what would probably be $700-$1000.
I ordered a new NVIDIA GeForce 7600 GT video card. The GeForce video card for this iMac has a special MXM PCI Express connector. So you can’t just pick up any GeForce 7600 GT or 7300 GT. Only WeLoveMacs.com appears to sell the correct video card.
Screws Galore
The iMac has lots of philips and hex screws of different sizes. I used these baggies and labels so that I could reassemble the iMac. I do the same thing when taking apart a laptop.
Hard Drive Upgrade
While I had the iMac opened, we upgraded from a 500GB to a 1TB hard drive. This required prying off the hard drive’s heat sensor and reapplying it to the new drive with rubber cement.
Not an Easy Job
The video card unfortunately is underneath the motherboard, which Apple refers to as the “logic board”. It is much easier to bring an iMac or MacBook to Apple for repair than attempting it yourself. Even if you are somewhat skilled, the process takes hours. But if you have an out-of-warranty computer, this could save you some money.
Because there are no other photos of the internals of this iMac online, I’m posting a bunch here:
NVIDIA GeForce 7600GT is MXM II; GeForce 8800 GS is MXM III….
i’m having the same symptoms as everybody. i also have a late 2006 with the 7300g card. I found this video on youyube with my same symptoms. is this related to the video card? http://www.youtube.com/watch?v=3j-tZ_v1aCc
Yes Eric Kinney, these two cards has a different physical form factor, MXM II vs. MXM III.
But that’s NOT the problem, – inside of these 24″ iMacs should be enough space.
The root of the problem is definitely the “MXM to logicboard EFI communication”. I read somewhere that the white iMac MXM (1Gen) modules are talking to the logicboard according EFI 1.10 specification, while the 2007/2008 ALU iMac MXM (1Gen) modules are talking according EFI 2.xx, ALTHOUGH they only have EFI 1.10 level… >:(
To Aurelio, check this site: http://www.flickr.com/photos/litmus/4480251432/
For every affected user, the following site would be also interesting:
http://www.petitionspot.com/petitions/imacrecall
thank you for your reply.. I guess i’ll try that before replacing it..
You can petition all you want but its a little late……5 year old machine??!?
I replaced my card, the iMac is as good if not better than ever. Not the only MAC in the house but I use it every day. If you want a gamer, go buy one.
Replacing the card DOES solve the issue at hand.
Before considering a complete card replacement, did some some of you tried to replace the thermal grease on the GPU ? (as it looks as if this is the main issue with this NVidia 7300GT)
see there : http://www.flickr.com/photos/litmus/4480251432/
Rick, hey thanks so much for the info and the pix. Upgrading my lil friends machine today. Was wondering just how to get at.
Rick,
Do you know anyone in the NYC/NJ area that you can recommend to do a replacement on the NVIDIA GeForce 7600 GT video card? Thanks.
I don’t. Anyone have a recommendation?
Abhi, I don’t know this place personally, but I saw in another thread on the iMac video problem that someone recommended “L2 Computer Inc, New York, NY”. Like I said, I’ve never used them, so look into the reviews.
I have opened mine but I cannot understand how to make the screws holding the GPU to release, see photo here: http://www.techdc.com/wp-content/uploads/2008/08/imac07.jpg
4 x black plastic topped screws? with springs under them.
I need to release these so I can turn the GPU over and replace the silicone.
HOW do I remove these spring loaded screws pls?
Is there any option like this for the 20″ Intel Imacs with the ATI Radeon x1600. I keep readin that our only option is a full logic board replacement.
Thanks,
Russ
@DDD – the black heat sink is not part of the GPU. The graphic card on the 24 inch iMac is a separate card underneath the logic board. You will have to remove the whole logic board to get access to it.
@Russ Peters – the 24 inch iMac has a separate and replaceable video card, the 20 inch iMac has a video card/chip that is soldered onto the Logic board, requiring the replacement of the whole logic board to replace the video card/chip.
Hope this help.
Adam