Bizzarre iMac overheating issue

As the temperatures climb, my iMac started to exhibit some really weird displays of artifacts, pixelated icons and fragments of windows embedded in one another. It got steadily worse, until one night while I was in the middle of a labour-intensive photoshop session (on deadline!) my document became distorted and fragmented with a spray of CMYK confetti everywhere. Panicking, I called a friend who's rather a Mac guru. Apparently in a small percentage of 24" iMacs sold before 2008, there was a substandard solder used on the logic board, which melts at high temp... causing all sorts of weird misfires (sort of like computer M.S.). Some people spent hundreds and hundreds replacing the board only to encounter it again. Much searching of the internet revealed this valuable information:

http://getsatisfaction.com/apple/topics/intel_24_imac_screen_problems

Basically, there is a program you can download to control the Mac's ambient temperature by changing the fan and operating speed. It's not quite enough though, I still found that even with a fan directed at the back of the machine I was still seeing artifacts after a couple of hours work – albeit not nearly to the same degree. Going into the system folder during safe reboot, and moving all the files labelled "geforce" to another location... completely solved the issue. No problems whatsoever. However... I can no longer run You Tube videos, or play Scrabble on Facebook :-( For some reason... my work output seems to have increased...

You might just need to clean the dust out of the heat sinks on the graphics card and CPU to bring the temps down. If there is a cooling issue with the design - a little case modding with a fan to flow some air will help or you can pry it open and do a liquid cooled solution:

http://www.newegg.com/Store/Category.aspx?Category=11&name=Fans-Heatsinks

I'd at least clean the hell out of it and increase the cool air flowing thru the cabinet. Removing the "Geforce" files is hobbling your NVidia Geforce graphics accelerator. That is like unplugging a couple spark plug wires to make your engine run cooler.

Thanks, I'm going to try that.

We had the same problem with that exact model and year range. Downloaded the fan control, blasted the dust out and improved the airflow to the back.

6 months later, dead Mac. We have a 5 year old HP laptop... still running. Don't know if we'll ever buy a Mac again. And of course, this happened just after the warranty expired. I'm sure that paying the "Mac Price Sachet" for faulty equipment will influence our next purchase.

Mark

Gee I've had Macs and PCs since 1984. At the end of that period the grand total is 0 dead Macs and 6 dead PCs.

And that doesn't even begin to address the amount of time working on and fiddling with the OS of the PCs. Nor does it count the money I've had to spend on virus programs and other "specialty" programs to keep the PCs running.

I'm down to 1 PC, 1 Mac that runs Windoze & Mac OS plus assorted other Macs. My time is my own.

If it's any help... I've owned at least 20 Macs, and this is the very first issue of this kind that I've had. No problems whatsoever with the others.

I might also try piggybacking a laptop cooling fan to the back of it. Right now it's working flawlessly, even with huge pshop files, with an ambient temp of 38 degrees. Apparently, it gets funky over 42.

oh jeez.. do we need to get into another MAC vs PC thread?

Shame that apple put that board out there.. and there is a known problem with it.. but won't lift a finger to help? At least a couple hundred off of your next purchase would be nice.

If we are going to go into PC vs MAC... something to keep in mind with dead PC notebooks.. a LOT of them are dead cheap.. and you get what you pay for.

I love Mac - and have worked on both. I also love my cats... and understand why my neighbour prefers dogs.

I don't think there is an issue with the case design per se (I used to have a 2008 iMac) but blowing out the dust does sound like a good idea from time to time. It's amazing how much dust and junk tends to accumulate in a computer case.

That said, ambient temperatures like you encounter are going to be an issue for most hardware, especially with compact machines like iMacs and Notebooks. My MacBook certainly runs the fans a lot more often in these temperatures, too. As does the Dell desktop (to be replaced by a used Mac Pro sometime next week).

Agreed, my Macbook gets so hot, it's uncomfortable resting it on my lap.

My little icon in the corner (thanks to smcFan Control) reads 35 degrees... and it's a really hot day today. No issues, and I've just completed another marathon, multi-layer pshop session.

I was having overheat problems with my desktop system in the spare room over the garage. A 5100 BTU room air conditioner fixed it!

Lesley wrote: I love Mac - and have worked on both. I also love my cats... and understand why my neighbour prefers dogs.

You know that makes you a racist, right?

Lesley wrote: I love Mac - and have worked on both. I also love my cats... and understand why my neighbour prefers dogs.

I have dogs. I never understood why anyone would want cats. They're more expensive, no better, and while they're good at what they do, and may have been better at one time, they have limited use. I've had the same dogs for 10 years without any trouble.

I like birds.. with no trouble for over 5 years..

I had an Acer laptop that started getting flaky when it warmed up. A good cleaning of the heat sinks and fan took care of it. I would start there. It's amazing how much dust a computer will suck up.

As far as dead computers, every one I have ever killed is still dead.

The only issue with aluminum iMacs is that to get at the motherboard (and HDD), you'll have to take the screen out...

Mine's a white Plastic model.

The GRM solution here would be to disassemble the unit to expose the GPU, heat it up with a torch to re-flow all the solder, then reassemble with quality thermal paste.

Yeah I know... not a chance.

A lot of the white iMacs also have capacitor problems in the PSU and on the motherboard. I have one (given to me) waiting for me to attempt to replace the capacitors. Hopefully it will work.

mad_machine wrote: I like birds.. with no trouble for over 5 years..

Whatever, you act like they're great, but I know you guys all have to spend like 50% of your waking hours feeding your penguin, cleaning his cage, picking things out of his coat... and god forbid he ever gets startled, you have to have a college degree in internal penguin medicine just to get him breathing again. Never mind all the confusion about what sort of penguin is the best, and the chance that your penguin might not get along with any of your friends' penguins.

Besides, everyone knows cats the best because they're shiny and pretty.

Josh wrote:

mad_machine wrote: I like birds.. with no trouble for over 5 years..

Whatever, you act like they're great, but I know you guys all have to spend like 50% of your waking hours feeding your penguin,

It has been my development desktop for the last 10yrs. The penguin does not need much as long as you have stable hardware... behold the magnificence:

$ uptime
20:13:41 up 612 days, 17:18, 2 users, load average: ...

I was mostly just having fun making penguin jokes. I liked linux for the several days that I played around with it on my Dell netbook before going all hackintosh on it :).

I have used both IBM and Mac PCs. Starting with the Apple IIe with basic programming in school. Sadly, I was the only one who password locked the diskette with a 5 try loop that said "HAHA! Take that sucka!" after the 5th failed attempt. The teacher thought it was funny. Anyway, 1 Mac, and 5 IBMs, none have died on me after heavy overclocking, multitasked to the maximum and in a hot room with no A/C. Would usually just build a new comp before the old one died and then give the old one to the local Goodwill store. After a good HDD wipe of course.