Is my NVIDIA GeForce 8800 GS graphics card bad?

I was having similiar problems - and now the NVIDIA GEFORCE 8800 GS W/512MB video card in my late-2008 iMac (The 24" version, model EMC 2211) seems to have finally given up on life. When I boot up the computer I get everything from black screens to white screens to multi-color static weirdness, along with sad chiming beeps on occasion.

Has anyone found a good guide on how to replace the graphics card/video card/GPU on these old aluminum iMac models?

The NVIDIA card in question is Apple part #065-7738.

But I don't know where the best place to order it is - or the safest way to install.

Any advice would be appreciated.

I'll probably get a new iMac when the new models coIme out. But I need to figure out how to get this one working again until then.

Such a shame that Apple allowed these faulty NVIDIA 8800's into these fine machines - outside of the glitchy, overheated graphics card the rest of the iMac looks new and was still working like new.

Hi Becjr

I live in Denmark so the cost for labor and parts is considerably more expensive than in the US. I arranged the repair through apple so they provided me with the service center near me. Unfortunately that was a 30 min drive. You can find refurbished cards online from 300-500 , but I've pretty much had it with this iMac and will not spend any more money exchanging graphics cards which may or may not fail 2-3 years later. Apple needs to address this issue with a swap to a more reliable component or a complete swap. I'm guessing that dust accumulating in the cooling fan and heat sinks which cool the GPU, CPU and Power supply, was not taken into account during development of this design, this causes the components to overheat due to the fans programmed settings.

I brought my iMac to Genius Bar today. They were very courteous and helpful. However, they ended up wanting to replace the NVIDIA card even though I told them that this problem will keep on coming back because of the heating problem of that specific card based on what I have read in numerous forums. They are pointing to the possibility of having a logic board issue, too -- I told them that this is usually a misdiagnosis whenever there is a faulty graphics card for iMac early 2008 series. They agreed and they are hoping that it is simply a graphics card issue at this point. I do hope that simple replacement of the NVIDIA card fixes the issue. However, another option would be to give up if this doesn't get fixed and Apple might not want to replace it with a new machine (although I guess replacement of the entire machine might also be one of their options since we know that this is really a problem with NVIDIA in iMac early 2008 series). I am an iMac, iPhone, iPad, iPod, Time Capsule user and now I am thinking whether I should switch back to PCs instead of Macs if they don't take care of me this time....

Got my iMac today after getting a call from Apple Store last night. They replaced the graphics card as they have said. So far it is working. It is a bit slow so maybe I need to check the hard drive...

So far the iMac is still working. Thanks to the Genius Bar guys. I will update everyone else here if I still see any problems.

No, Becjr. It is no longer covered by any warranty but they replaced the graphics card for free since I never had any major complaints (only one minor complaint) during the Apple Care period. So far, the monitor has been turning off (18X now within a span of ~18 days since the time that I picked it up). It happens whenever I use Windows 7 (no cursor but I know that the iMac is still on because I had to press the power button for a longer period before I can turn it back on). Apple Genius bar suggested that I bring it back in but I just need the iMac really badly for telecommuting so I am trying to live with it for now. I installed MacFan_065 to take care of the fans and HW Monitor to see the temperature. Whenever I see the GPU temp go beyond 50degC, I put the iMac to sleep. Eventually, I have to bring the iMac to the Apple Store within the 90-day grace period.

By the way, I told them about all the things that I have read about NVIDIA GEForce 8800 GS having problems on how to handle heat despite its huge heatsink. I showed them printouts of the discussions in a forum.

Just to give you an update, I have been setting the speed of the fans using the command

macfanx64.exe 1200 2000 2000

and it has not turned off the monitor for about 4-5 days now so I am keeping my fingers crossed. If it still happens despite the higher fan speed, then I would really need to bring the iMac to the Genius Bar again.

I used macfanx64.exe 1200 1500 1500 before but it still kept on switching off so I increased the fan speed for the CPU and the HDD to 2000.

Ironically, after six days, the monitor turned off three times last night (only on Windows 7 side). I'll observe it again tonight.

In my opinion, this is still way better than not being able to use my iMac anymore -- I couldn't even boot before and see so many vertical and horizontal lines. I updated my Mountain Lion OS last night to 8.1 so let's see what happens. It usually does that when I use the roller of my mouse under Windows 7 (not when I am using Mac OS side).

Just had one replaced in my iMac 24 yesterday at King of Prussia Pennsylvania Apple Store.
Cost was $131.82 plus labor of $39.00

What I have experienced over the years is that the Apple Store Genius Bar service is the best way to go for any MAC repairs and such. They are quick, know what they are doing and have the parts needed.

Thought I'd sign onto this thread...same GPU issue with the NVIDIA GeForce 8800 GS in my Early '08 24" iMac. (iMac 8,1 - 3.06 GHz, 6GB RAM, OS X 10.8.2)

Last March the card began acting up and failed after about a month. I had been playing COD on it and that probaby sent it over the edge. I took it to the local Apple Store Genius Bar and they ended up replacing the card. Since the card is soldered to the logic board I'm not sure if they only replaced the GPU or the entire board, but like RASchafer they charged me $170 for parts and labor. I guess that's not bad for a machine that age...spoiled by our other Apple products I suppose.

I do edit some video and I also have an Apple Cinema Display attached as a second monitor so there is some stress on the GPU, but no more games so it's not that much IMO.

Recently it's started acting up again (see attached screen shots). It's frozen once now (although the Magic Trackpad cursor still moved around).

Reading the info on the back of the Genius Bar order the repair s/b covered for one year. It'll be a real pain to have to leave it for a week to be fixed again though.

I have iStat Pro installed to keep an eye on temps and I boosted the default speeds of the HDD and CPU fans to 1500 and that seems to keep the GPU a bit cooler (runs around 55c idle to 70c under load). Anything above that is annoying. Whenever I'm doing some video editing and get to the rendering stage I just crank them all up now and leave the room for a while becuase it sounds like jet engine.

It's a shame that Apple ever used these cards because the iMac has been awesome in every other way. From all of the research I can find, there's no other option...just have to get it repaired periodically I guess. Sad because all of our other Apple products, MB Air, Mini, iPad, iPod, iPhone have all been stellar. Although the iMac has been perfect otherwise, I just hate having this issue in the back of my mind, worrying about it whenever I see the slightest glitch. Guess one of my dual Time Machine backups will have to be put into service again one of these days. 😟

My experience was very similar to RAShafer. Called several Apple certified shops but was not left with a confident feeling. One store even told me that the graphics card on this iMac could not be replaced and that I had to buy a new iMac. Decided to drive 90 minutes to the nearest apple store. Good call. They said it was for sure the graphics card but could involve the logic board as well.

We set up a plan to change the graphics card but they would call before doing anything with the (much more expensive) logic board. I would have the option to cancel the entire repair, at no cost, if I decided it was not worth the cost of both components.

Dropped it off on Friday night and they called me on Monday night to pick it up. $131 plus $39 for labor.

Pleasantly surprised, indeed.

Thanks I'm happy to hear that your NVidia Card is working well. I thinking of upgrading, and there are a lot of negative reviews on line with respect to this card. I currently have a ATI Radeon HD 2600 Pro 256MB, whic I want to upgrade to the "Apple 661-4664 Video Card, NVIDIA GeForce 8800 GS for 24 inch 2.8-3.06GHz". Your's is one of the few postivive comments I've read. THANKS!