2008 iMac Continuing Issues

I just started having this problem. The display just turns off randomly. Some times it will come back on it's own, but other times I have to reboot. Based on the audio, it appears that everything else is still working. Music still plays and the keyboard works. I hope it isn't a logic board failure...

Shortly after my last post, the video card died. I get lots of white, gray, black garbage on the screen. The whole machine locks now too. The good news is that AppleCare is picking it up on Monday...

TK4108,

Do you guys happen to have nVidia 8800 GS in your iMac?

Yep. It is coming back from the shop on Monday. I'm wondering if it will still have a 8800 GS in it...

It still had the 8800 GS. Better yet, it just died again, less than a month after the repair...

Oh man, no wonder Apple completely eliminated nVidia's crap from their latest Macs. I was thinking about getting a repair, but choose ATI Radeon HD 2600 PRO instead. My card still works though, but I don't have black and some other color shades. There are pulsing red lines instead, which hurts your brain if you constantly look at it.

Here's an example:



Good luck with your iMac TK4108.

Are you still having issues? Was it fixed by taking it in? I am experiencing the same problem. The screen goes black, the machine is on, I still have sound, but obviously cannot see anything. The only thing I can do is shut it down and reboot by pressing the big power button in the back. I am am worried the problem is a video card.

What an I run to check it out? The strange thing is that it only started doing it in the last two weeks. It has happened once of twice before, but not as often as it does now. I have heard it might be a driver issue with newer updates, but I am worried it is hardware.

Unbelievably, yet true, my iMac only needed LVDS cable replacement. I got my black (and other) colors back. Still can't believe the fix was only about $32 away. Replacing the graphics card would cost a fortune. Now off to watching movies.

Same Imac (8,1) Same spec. (8800gs) Same issue (Losing picture, graph anomolies, freezing)

It must have overheated to the point of damaging the GPU because it crashed once in Windows 7, then screen goes black (or blue, purple, grey on occasion) after login to either Windows 7 (Boot Camp) or OS X. It even does it booting from Leopard disk to run Hardware Diagnostics. I have to let it cool down for an hour or so.

Kicking the fan RPMs up by 1000+ makes a noticable different in run times before it freezes again.

No Applecare.

Did you ever get this resolved?

Was that with Applecare or no? I need mine fixed, but don't want to pay $1000 for a new logic board. This would be my third time bringing the iMac to the Applestore in the 2 years I've had it.

Similar problems, also on a 2008 iMac with the 8800 GS.

It's run fine for 2+ years. Today, after installing an OS X update with the new Java RE, the screen went wonky (rapid blinking, different colors, etc.) and the mouse and keyboard became unresponsive.

I called Apple, who ran me through a variety of tasks that culminated in re-installing OS X. Half way through the re-install, the same effect showed up on the installer, and the system froze. Now I have a dead iMac.

I thought I had AppleCare--we've bought it on ALL of our Apple products, and we have many. I found where I inquired to our Apple re-seller about getting it, and I have an invoice, but no record of a care #. I have the vendor looking for it now in his records, and Apple said they could retroactively apply it to my iMac serial # if I can provide proof of purchase (which I can). Just a pain, really. Hate this.

iMac 24" 8,1 core duo 3.06 w/ Nvidia GeForce 8800 GS
Purchased mid 2008, so owned just barely over 2 year mark.

Wall-O-Text incoming...

I recently had similar issues (Nov 11th)... Just after the new osx update.

My screen began to artifact, pixels everywhere and audio would get caught in a loop, then finally the machine would just lock up. Sometimes this would happen with Photoshop open, sometimes, just copying or moving a file. The only resolve was to hold the power button.

Needless to say, it was dead. The screen artifacts and garbage were even present while running the Apple Hardware Test. The test showed nothing the first 3 times it ran. The fourth yielded a failing hdd. ( to be honest, I was experiencing issues near the end of October - pre 10.6.5 - but nothing this severe ).

I took it to the 3rd street Apple Store in Santa Monica, where they tried their best to help resolve everything quickly. It ended up being in their hands for a week, and the hdd and graphics card were replaced for roughly $640 (they dropped the price by $100) out of apple care (I never needed it over the past 13 years : live and learn).

I got the machine home on Nov 20th. All seemed well. It started up just like I purchased a new one (clean install) and lasted... a week.

On the Nov 27th(after applying the recent OSX updates again), something new happened. This time, the entire lower 50% of the screen started to flicker black over and over, until eventually, locking up. OpenGL log errors galore. I've seen some of the similar garbage on screen prior to the graphics card replacement, and am now about to drop kick this machine.

I'm almost resolved to the problem being with the logic board, but can't help but think that something in the latest update was the catalyst. Any updates tend to make the machine freak out again... I keep wiping and starting fresh. So far, 10.6.4, and 10.6.5 will eventually reproduce the issues. I don't understand at all.

I don't want to replace the logic board, as that will inevitably make me a sucker because I could have just bought a new 27"instead of lose nearly a month of work and play over this BS.

About to give up...