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iMac Graphics Crash

G

grrMacr

macrumors newbie
Original poster
Feb 20, 2012
2
0
Newbie here. My Imac is doing this.

screen copy.jpg


Imac 21.5" (mid 2010) 3.06GHz/16G RAM/500G HD. This is an ex-display model (which in itself may suggest something to you tech wizards) which I bought only 6 weeks ago. It came with Snow Leopard and this screen crash occurred more than once on day one. I immediately upgraded to OS X and it was stable for a few weeks so I was reassured but exactly the same screen problem has recurred recently.
The screen does this apparently randomly, i.e. when sitting untouched, when online and when mid-game.
I have:
-verified/repaired HD (no probs identified)
-repaired permissions
-reset NVRAM
-run fan control app (all 3 fans respond to increased revs, temp max 55C)
-run GUI memtest ("rember") = no probs with RAM
-then CLEAN INSTALL of os x and repeated all of the above
-run apple hardware test (basic = no probs found, more complex = has been unable to complete as this issue has developed on three consecutive attempts mid-test)

Forum wisdom I've come across so far has left me unclear as to whether this is hardware or software. Clean install suggests hardware, but apparently this is highly unlikely.

No apple care but extended retailer warranty theoretically covering this but naturally I anticipate they will do everything to avoid taking this on. Plus I want to make a good case for when I phone them by exhausting everything I can do myself so hoped someone out there might be able to offer some other interpretations of this problem or suggestions.

Kinda out of ideas here.

Thanks.
 
Same here except my iMac (2009 2.93 C2D) was completely fine on Leopard and Snow Leopard. I upgraded to Lion, BOOM. Issues non-stop. I've run the same things as you and nothing comes up. I've been deleting applications all day that have been coming up on kernel panic logs. The ONLY thing i seem to gather from it is that it only does this when i have a browser open. Rather it be Safari, Chrome, or Rockmelt. Any other time, i rarely see crashes or kernel panics. I played Minecraft earlier because if it's graphics card related, surely Minecraft would push it to crash faster than an idling browser. Nope. Minecraft played fine for an hour. I just now uninstalled Flash and it seems ok so far. (Chrome somehow had two versions of Flash installed) Drives me nuts. I even re-seated my RAM (tested it earlier) I'm out of ideas. Hopefully someone comes up with something we're both missing.
 
I had a similar problem to my previous iMac. Although an older model, the symptoms were pretty well identical. As with your machine, the iMac would run perfectly for a considerable period and then, without warning, would exhibit the problem. Switching off, leaving the machine for a while and the rebooting would often fix things - until it misbehaved again! The frequency of the problem gradually increased until I took the machine to my local Apple Service Centre. They carried out diagnostic tests and identified the problem to be in the video section of the logic board.

I had a new logic board fitted (complete with a 90 day Apple extended warranty) and the machine ran perfectly until I replaced it with a new model.

In short, my advice is to take your machine to your local Apple Service (details on the Apple website) and they will check the machine out and give you a free quotation for any necessary work to be carried out.
 
i have the same problem

i have mid 2011 27" iMac.

exactly the same problem.

did everything.

aht reports no problem in both simple and complex mode.
i have reinstalled lion and installed all of the updates.

i have lion 10.7.3 + bootcamp with windows 7 and both of them are updated.

help me please.
 
To the Original Poster: Even though we have quite different iMacs, your problem sounds so similar to mine and others' that I advise you to have the extended warranty repair it right away, or, better yet, get your money back if you can. (Because the repair people may not be able to reproduce the problem.)

To cocky jeremy: Your 24" iMac is similar to mine and others' who have had recurring "screen freezes". There's a 67-page thread about this issue at https://discussions.apple.com/thread/2384136?start=0&tstart=0. It's a lot to wade through, but the bottom line is that if you have the same problem, there is a "fix". It involves using the graphics drivers (some kernel extension or "kext" files) from OS X 10.6.2 with later releases of Snow Leopard or Lion.

Actually, the problem in the Apple thread seems to be a combination of hardware and software, as the above mentioned kext fix has resolved it for many, but also replacing the graphics card has also fixed it for a few people. (My imac still had a separate GPU card, not sure about yours.)

Brian33
(Brian from VA on the Apple support board)
 
This is a video card issue most likely. You can test this a few ways....

When it does it again, press the volume keys up and down and listen for the "plick plick" sound (if you have that sound disabled, hold the shift key when you press the volume keys) If you don't hear anything then the machine essentially kernel panicked.

If you have another Mac on your network, you can try to screen share to it when it does it again. If its a video card issue, you won't be able to see anything on the screen share. If its just a display problem you'll see everything like normal.

My guess is video card. Good luck!
 
More

For other sufferers : Apple tech (Glasgow) says this model (11,2/A1311/EMC2389) has separate GPU. Looking at my original post he reckoned the problem is definitely either logic board (£500ish plus time) OR GPU (£350ish plus time) but no way to be certain it's only GPU.

ifixit.com + diy does look very useful but I will only find the stomach for that if extreme last resort.

Thanks very much for your replies, guys, and good luck.
 
I will say that in my experience this issue is almost 95% of the time video card related. Also, on that model of iMac, this is in no way an easy repair. There are a couple of cables that connect to the back of the logic board that are very tricky to get back in place. And, just getting the logic board to seat back down in the housing is very tricky, especially without flexing the board and damaging it.

I can't, in good conscious, recommend you do this repair yourself.
 
John T said:
I think you'll find that the graphics card is integrated in the logic board.
Click to expand...

It is on some, but most of them have a separate graphics card. If the problematic machine is one of the ones with a separate graphics card, that's what you should order, as replacing the logic board on a machine with a separate graphics card is not going to fix a graphics issue.

----------
grrMacr said:
For other sufferers : Apple tech (Glasgow) says this model (11,2/A1311/EMC2389) has separate GPU. Looking at my original post he reckoned the problem is definitely either logic board (£500ish plus time) OR GPU (£350ish plus time) but no way to be certain it's only GPU.

ifixit.com + diy does look very useful but I will only find the stomach for that if extreme last resort.

Thanks very much for your replies, guys, and good luck.
Click to expand...

It's true that there's no way to be certain whether it's logic board or GPU without swapping out the GPU, but it's *almost* certainly the GPU, and by that I mean 99%.

People say that swapping out graphics drivers for older ones fixed their issues, but really what's going on there is that the older drivers don't use certain parts of the graphics card and therefore they don't instigate the crash in the bad graphics card. The graphics card is still the problem--not the drivers. This isn't an "extreme last resort"; it's "the fix".
 
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