Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Mac Pro overheating; can I replace the power unit fan?

After much strange behavior with my MacPro2,1 model I installed Hardware Monitor and discovered that the temperature readings for some of my Memory Modules and for the sensors on the Power Supply location 1 and Power Supply location 2 are very high. With no load the temperature is reading about 62° C on the "Power Supply Location 1" sensor and 85-90° on "Power Supply Location 2" sensor. I installed smcFanControl and found that I could cool the Memory Modules but even with all fans set on maximum speed the Power Supply temperatures droped only slightly to about 78- 80° C. All of the fans increased their RPM except for the "Power Supply Fan" which remains at 599 RPM no matter how high you set the Power Supply fan on smcFanControl.


All this leads me to suspect that the Power Supply Fan is either not running at all or is not able to accelerate in response to high temperatures in the power supply area.


My questions are these:


1. Can I visually confirm that the power unit fan is not working? That is, what do I need to do to actually visualize this fan in question and see if it is running? Is there another way to confirm that the fan is bad aside from just inferrring this from the high temperatures and findings in smcFanControl?

2. Is fan replacement a job that I could reasonably expect to perform myself or do I need to take it to an Apple repair shop? I have replaced hard drives and RAM in Powerbooks and a Mac Mini, installed PCI cards, etc.


3. Are there diagrams and/or instructions for doing this sort of thing?


Thanks.

John Baughman

Mac Pro

Posted on Nov 3, 2012 4:03 PM

Reply
Question marked as Best reply

Posted on Nov 3, 2012 5:26 PM

The side door is not interlocked, and can be removed with the Mac running. No hazardous Voltages are available to your unaided fingers, but components may be HOT.


Airflow can be improved by blowing out the dust bunnies with compressed air. Do this in a "don't care if it gets dirty" location ONLY. Airflow also improves slightly if your unit has only ONE Optical drive instead of two.


One some models, the power supply fan speed is controlled by the power supply itself, not by system software.

3 replies
Question marked as Best reply

Nov 3, 2012 5:26 PM in response to John Baughman

The side door is not interlocked, and can be removed with the Mac running. No hazardous Voltages are available to your unaided fingers, but components may be HOT.


Airflow can be improved by blowing out the dust bunnies with compressed air. Do this in a "don't care if it gets dirty" location ONLY. Airflow also improves slightly if your unit has only ONE Optical drive instead of two.


One some models, the power supply fan speed is controlled by the power supply itself, not by system software.

Nov 3, 2012 5:43 PM in response to Grant Bennet-Alder

G B-A,

Thanks for your response. I'm beginning to believe that the fan may not be defective after all. Heat management was always a concern even when this model first came out. I suspect that the reason I can't force the power supply fan to run faster is exactly what you have stated- it can't be controlled since it is not controlled by software. I tried to use compressed air to blow out dust. But I think I may have to be more aggressive. Perhaps I can remove some of the covering and better expose the area where the power unit is and maybe actually see the fan? I'm assuming this is all behind the covering that is over the area of the 4th (rear) drive bay. I'll need to research to see how much of this can be easily disassembled. It looks like I would have to remove the two optical drives first to get access.

John

Nov 4, 2012 3:08 PM in response to John Baughman

John Baughman wrote:


... 1. Can I visually confirm that the power unit fan is not working? That is, what do I need to do to actually visualize this fan in question and see if it is running? Is there another way to confirm that the fan is bad aside from just inferrring this from the high temperatures and findings in smcFanControl?

2. Is fan replacement a job that I could reasonably expect to perform myself or do I need to take it to an Apple repair shop? I have replaced hard drives and RAM in Powerbooks and a Mac Mini, installed PCI cards, etc.


3. Are there diagrams and/or instructions for doing this sort of thing?...

If you only have one DVD drive, you can shine a bright light straight back through the lower drive area where you'll see a screen with fan blades behind it at the rear end of the SuperDrive cage. That's the power supply fan at the front of the power supply. You should be able to see it spin when you power up. I found that smcFanControl couldn't control the PS fan on my Mac Pro 1,1 either (it does work on the 5,1's PS fan). If you remove the SuperDrive carrier, you can get directly at the PS fan for more effective dust removal.


Diagrams and instructions for how to do that and much more can be found here http://tim.id.au/laptops/apple/macpro/ which is a source of Service Manuals. X423424X gets the credit for posting that link; I just bookmarked it.

Mac Pro overheating; can I replace the power unit fan?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.