Q: Late 2006 iMac, Lines, Kernel Panic, Freeze, Reboot, Restart, Serial W8 ?

overheating of the graphic card is defo the problem. I have installed the program yesterday. For the first time in months my imac hasn't crashed or showed any awkward lines 24hrs.

Alright, I till install smcFanControl. What do you suppose I set the fans to (1000-6000RPM)?

Add me to the list. My specs where I've been experiencing all of the above problems for quite a few years: Apple iMac 20" A1207 Late 2006, 2.16GHz Intel Core 2 Duo, ATI Radeon X1600/256MB VRAM, purchased September 2006. I sure hope Apple will do something for us. I just recently bought a new machine (an iMac again) because I couldn't take it anymore.

Just installed/set up smcFan. Made some standard controls (2500, 3000, 4000, and MAX) and performed some tests.

Firstly, I ran the Mac until it died, mainly using the Dashboard to perform graphically-intensive tasks, while still monitoring the temp. It finally quit after about 20 minutes, showing 128˚F on the GPU; standard maximum temperature.
Then, I ran the same procedure with the 3000 setting. Same thing happened, though it lasted about 23 minutes. Not exactly stellar, I'd say.
Next, I ran the procedure again at 4000. It survived approximately 30 minutes. Interesting...
And finally, I ran it again, this time at max. It died after about 40 minutes.

From these tests it has become clear that the fan is not the one solution to this problem. Another test proving this:

I ran the mac until it was at >120˚F and displaying major graphical issues. I then quit all programs immediately and ran the fans at the 3000 setting for ten seconds. The temperature remained constant, not falling. I ran the fans again, this time at max for ten seconds. After the 'burn', the GPU read 118. Obviously a small decrease. (NOTE: All other components were displaying temperatures of over 80 degrees before the burn, and under 70 degrees after it.)

So due to these results, will I have to run the fans at max as long as i wish to use the computer? Because those are fairly annoying at 6000+RPMs.

EDIT: Could I make a fan specifically for the GPU? That seems like it would help alot more than using the CPU/HDD fan.

Message was edited by: UltimateCole

UltimateCole wrote:
From these tests it has become clear that the fan is not the one solution to this problem.

Once the lines and crashes have started, smcFanControl can't fix it. The damage is already done. You may postpone the crashes a bit longer but the GPU damage can't be undone. smcFanControl may prolong the life of the GPU if it's installed BEFORE you get any problems appearing. When I say 'GPU damage' it may be a solder issue according to some reports. Poor soldering techniques may result in an imperfect contact which with repeated expansion and shrinking could possibly cause the issues we've been having. The GPU itself may be OK but it's of little help, unless you're tech savvy enough to go through the solder re-flow procedure.

Model Name: iMac
Model Identifier: Late 2006 20"
Processor Name: Intel Core Duo
Processor Speed: 2.66 GHz
Serial Number (system): W8651

I have been having the same problems as most users-freezing, pixelation and so on. But I think I have temporarily solved the problem, I placed the Imac over my A/C & Heating vent on the floor and as long as the A/C is running the computer runs glitch free. The downfall to this method is that I'm now suffering from chronic aches and pains in my back and neck and my chest gets really sore from lying on the floor, so I can only stay on the computer for 10-15 minutes at a time, also winter's around the corner which is making me very anxious.
Please Apple fix this problem before I get seriously hurt.

Ah crap. Well, I guess I'm gonna have to get the GPU replaced. What's something like that cost, minus the labor? I understand the mac I have uses a Radeon X1600, could I get that swapped out for something new?

@UltimateCole
If you only could replaces the GPU. I've would have done that immediately.
But the GPU is intergrated to the motherboard.
Replacement of the motherboard with Apple will cost $900,- or €800,-.
You'll have a great computer for that amount of money.
One problem... if you replace the GPU the problem will appear again.
Because heat is mean. It doesn't only do damages on the GPU.
Question what is next.

$900, are you kidding me? That's rediculous! I could get a new macbook on amazon for less than that! Or almost an entirely new iMac! Man, why do macs have to be so expensive? Windows is much cheaper, but I've been betrayed more than once by their horrid OS. Gah!

I started having this problem earlier this week (lines, Kernel Panic, freezes)--perhaps not coincidentally with unusually hot weather around the Bay Area. I spent a while reading this thread which seems to cover a lot of what we're talking about here. http://discussions.info.apple.com/thread.jspa?threadID=1467276&start=0&tstart=0

Maybe I'm getting the terminology wrong, but this problem is often linked to "Late 2006 iMacs." I don't know if that means iMacs limited to late 2006, or if it describes the release date of the affected models.

The reason I bring that up is that my iMac serial number decodes down to an early 2007, not late 2006. The particulars:

24" white iMac
2.16 Intel Core Duo
NVIDIA GeForce 7600 GT

I went through the whole process with the SMC fan control, and seem to have solved my problem for the moment. Bummed (but maybe not surprised) to read that it's probably not a permanent fix.

I don't have a huge sampling of when/what temps caused my problem, but as I was surfing the web looking for info, I was getting horizontal lines with the GPU diode reading 69c/156f. I now have the fans at ODD2300/HDD3000/CPU1900, and the GPU diode is at 53c/127f. No problems so far.

Like many others, my Mac was trouble-free until last week. Since this problem seems to ramp up over time, I think we'll see more and more of these issues. I figured I'd check in just to have my name on the list, plus to clarify that the issue is most certainly not limited to late 2006 iMacs (again, unless I've got the terminology wrong).

Hopefully, the most people that pipe up, the more likely there will be some kind of resolution from Apple. Or, at the very least, some kind of standard fix that will work over a longer period of time than the 2-4 years that seems to be the limit of the factory setup.

The basic problem with this is trying to tell a design defect from the normal rate of failure of aging computers. The older a computer is, the more likely it is that it will fail, so to reasonably attribute these failures to a design defect a large percentage of all of those in use must fail. With hundreds of thousands of each model in use, that means a lot more than several hundred failure reports would be required to show this.

I've got the same feeling that it doesn't stop with the models of 2006 iMacs.
*IT IS HUGE!*

Google for imac X1600 graphic defect, imac 7300GT graphic problems (flickr), and imac 7600GT graphic problems, Macbook pros X1600 graphic problems, Macbook Pros 8600m graphic problems.

Class action suit is settled with MacBook Pro (May 2007 and September 2008) GPUs NVIDIA GeForce 8600M.

elice82@ wrote:
Class action suit is settled with MacBook Pro (May 2007 and September 2008) GPUs NVIDIA GeForce 8600M.

This suit applies only to specific MBP, Dell, & HP laptops, concerns a defective chip used only in those models, & does not involve Apple, HP, or Dell directly. For the details, see http://www.nvidiasettlement.com/index.html.

Count me in on this problem. I have a late 2006 iMac C2D 2.33Ghz with the ATI X1600 card in it and I get horizontal artifact lines especially in browsers but sometimes in iTunes. If I play Half Life 2 or Portal then it is a surefire way of crashing the machine hard (have to hold down the power button to reboot it).
It is totally unacceptable that Apple knowingly are allowing this situation to exist without some form of remedy. Considering the high price point they charge for their products, one would expect them not to self destruct in this manner without any abuse or misuse. My machine has been kept in a clean, smoke free office but has / is failing after periodic use. It is unacceptable.

Apple, please get your act together and sort this out and offer repairs for the demonstrably failing machines.

{quote:title=24LeMons wrote:}
Maybe I'm getting the terminology wrong, but this problem is often linked to "Late 2006 iMacs." I don't know if that means iMacs limited to late 2006, or if it describes the release date of the affected models.

The reason I bring that up is that my iMac serial number decodes down to an early 2007, not late 2006.

{quote}

"iMac G5 (Late 2006)" is the string used to identify this specific model of Mac, e.g., so you can identify the appropriate service manual for that model as opposed to some other model of iMac G5. Any identical iMac made from that point on, even into 2007, is still going to be called "Late 2006" until there is a significant design change that requires a new service manual. This is true of all Mac models. If you type your serial number into the "Self-help" area of the support website, this is the string that will be reported to you.

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