Imac 24" early 2008, CPU heat problem

Hello everyone,

I use my iMac a lot and even more these days for audio purpose. When I do so, my good old iMac begins to accuse his age and the cpus are running wild...and not only that, the rest of the components are also getting hot.

With SMC Fan control, I often need to push the fans to the limit when I have a lot of plugins running at the same time. I tested individually the 3 of them and they are all fine, so it is not the source of the problem. 3 months ago I was using around the same amount of plugins without this overheat problem.

3 parts of my iMac have been changed:

The graphic card was a Geforce 8800 and like a lot of you already know, those are a real time bomb. I had to downgrade my video card to the ATI Radeon HD 2600 Pro(I actually like a lot more this video card)

I upgraded the ram with 2 X 2GB

The Initial Western Digital HDD has been changed for a SEAGATE 2TB model ST2000DL003-9VT166

Also I cleaned all the fans when I changed the HDD in summer 2011.

I performed an extended Hardware Test a couple hours ago and an error came up:

4MOT/2/40000006:HDD-1369

Looks like I got an Hard drive problem. Is it a separate problem? I have no clue for now.

Somebody on another forum wrote the following:

I had a similar problem, turned out that the temperature sensor of the HDD was broken (even though iStat reported CPU fan). The HDD needed to be replaced to fix this (luckily I have AppleCare).

Would it be possible that the problem is coming from there for that error? Is there a way to know more about this?

Maybe I need to change the cpu paste? I really don't know. But now working on my Mac is a little bit stressful since I always need to monitor all the components temperatures with temperature monitor and SMC Fan. When I push the fans really high while composing, the heat of practically everything is between 50 and 60 degrees, cpu often over 55. I fear for the damage that this heat could cause and the sound of these fans is really killing my workflow!

Thanks for your time and future help.

Dom

 

Here's an example of heat jump that I get sometimes:
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It is really hard to come back to normal heat when it starts to warm up like that, I often need to close everything and wait.

Could that error with the hard drive be the cause? I did have some problems with the hard drive for a while, it seems really unstable if I compare it to my previous one that came with the iMac...

Thanks again for future help.

Dom

 

Hi Intell, thanks for your response.

The fans, during that moment, were all at top speed, and it was impossible to go down. I never had such a hard time with the heat of my components before. Right away when I use something that demand a fair amount of processing, the heat jumps high right away and if i don't push the fans to top speed, a kernel panic will pop.

So I don't remove the possibility of being that I am stressing for nothing, but this is the first time I have to deal that much with heat...

 

Hi GGJstudios, thanks for your informative post.

But as I said, I control the speed of my fans with SMC Fan. I got one automatic shutdown 2 weeks ago because I was working on audio and didn't monitor my temps. My fans speed werent fast enough but I was doing normal work...like work that I was doing some months ago without putting my fans at top speed(over 4000 rpm).

Intell, Apple didn't want to change my video card with the ATI, Apple only change a video card with the SAME video card...which is quite stupid since that Geforce 8800 was born to brake on every users after around 2 years of use...

So I had to go to a specialized shop called Dalailamac, and the tech that was supposed to do the job wasn't available, so it's another tech with less specialization for that matter that did the job.

I though he did it pretty good, since I didn't have any problem for a good 1 year.

Also, it is imporant to note that the hard drive has been changed by myself with a Seagate, and right now I know that I need to replace it because I got an error during the Hardware test and when I am working on video or audio stuff I often have some issues occurring like the rainbow circle appears for practically no reason and things like that.

If I change the hard drive again, could that solve the heatsink issue? Or it is really not related?

 

Thanks for all your responses, it is greatly appreciated.

Killerrobot, I just did a test with my fans. I put the HDD one to max and left the other ones on 2000 rpm. When I did that, I did clearly hear the rising sound of the HDD fan. I think the fans are fine since I clean my iMac once a year.

The probability of an issue with the dying hard drive being quite high now according to the responses on this thread will be my priority.

I will change it, but if you guys could help me to choose a good one for a price around 100$ and that is compatible with my iMac and not complicated to install, it would be really helpful since I don't want to get another HDD that doesn't last for more than 2 years.

Thanks again, you all rock!

 

Hello,

Alright, will do some meticulous research before buying anything.

Thanks for your help and thanks to everyone who participated in this thread...will come back when I will have changed the HDD.

Dom