EXTREME fan noise on iMac G5 since installing Leopard! Help!

I know lots of people have posted about this all over the net and no one seems to have come up with a solution, but I'll give it another try.

Anyway, my problem is that the fans on my iMac G5 (PPC) run like crazy ever since I installed Leopard. CPU activity seems normal - although the CPU temperature often goes up to around 58 C.

Please, does anyone have a solution for this?! I'm going crazy from all this fan noise and it's come to the point where sitting working at the computer is almost unbearable. I've tried resetting the SMU and I've tried cleaning out the dust, but to no avail.

Any help would be much appreciated. Needless to say, I'm pretty disappointed in Apple for first of all releasing an OS that doesn't seem to run properly on my machine and, secondly, for doing nothing to resolve the fan noise problem.

Thanks,
Dan

iMac G5 Mac OS X (10.5.4) PPC, first generation, 1.8 Ghz

Have you checked the activity monitor to see what was running? Something has to be causing the CPU to work hard which would in turn make the thermal sensors on the motherboard speed the fans up to provide additional cooling.

It's possible that file indexing is being accomplished since you just installed Leopard new. That should settle down in a few days though. If it's not file indexing then it has to be a program or process that's running in the background. If it's not any of those, I would suspect a hardware problem.

Apple has done extensive testing on the machines it states can run Leopard. If your machine could not handle Leopard, they would have said so. Your post is the first I've seen regarding the problem you're having and I participate in this forum and several others for Mac hardware and OS X software.

Regards.

Thanks for your reply. I've been running Leopard for probably six months now, so it's not an indexing problem. Nor is it a case of heavy processes running the background - at least not according to the Activity Monitor.

I've had this problem ever since the first Leopard install and I'm not alone:
http://www.google.com/search?btnG=Google+Search&q="fan+noise"+imac+g5+leopard

As for it being a hardware problem, do you have any clues as to what it might be? Running third party RAM units shouldn't be a problem, should it...? Adding RAM and installing Airport are the only changes I've done since buying the machine. As long as I was running Tiger everything worked smoothly - as it should.

Thanks again. I don't want to sound as though I'm whining, I'm just frustrated by the whole thing. But I do appreciate your input!

Hi:

Just spent some time reading thru various posts concerning fan noise on the G5. Looks like they're all a bit different. Some were caused by a faulty logic board, another - a loose connection, yet another - run away CPU process, etc, etc.

One guy stated he reset the SMP and that seemed to work. Another guy claimed it was dirt.... Not all the posts were from users of Leopard. I noticed several were using Tiger.

I would advise you to try everything that the other posters said worked for them. I still have serious doubts that Leopard could have caused the problem, but what the heck, I've seen stranger things happen with computers before.

You asked about a possible hardware problem.... It could be anything from a loose connection to a defective logic board. Thermal sensors do not usually go bad. If anything, it's probably on the controlling side and that points to the logic board.

If you find a solution, post back. Or, if you have any other questions I can help you with, post back here or send me email.

Regards.

Thanks so much for all your help! I really do appreciate it. I've tried all the suggestions I've come across in the various postings across the net but nothing has worked for me. So maybe I'm stuck with a hardware problem - which means a costly problem. Lucky me