Mac Pro A1289 PSU Fan faulty

Question

Level 1

8 points

Mac Pro A1289 PSU Fan faulty

Hi.

I have a Mac Pro A1289 that randomly shuts off. I suspected the PSU unit was failing and a search of the forums yielded a few with the same issue that turned out to be the PSU. I took my unit apart and realised that it wasn't the PSU itself but rather the fan in front of the PSU that wasn't working, hence the PSU was heating up and shutting off due to its thermal protection. Easy fix i thought, just get a replacement fan and i'm done.

Easier said then done.

A search for the fan unit has yielded zero results. I'm able to find the PCI fans, the cage fans etc, but no one seems to be carrying the PSU fan.

Anyone has any ideas where I can get the replacement fan or has purchased one before and can point me in the right direction?

Any advise appreciated.

Thank you!!

Posted on Nov 26, 2015 11:03 PM

Reply

Answer 1

Nov 27, 2015 11:29 AM in response to ^Tripper^

From the fan's label information, you can often find a description of the fan in air moved in cfm and noise generated in dB. You can measure the size bolt-to-bolt along the edge in mm. All these fans will be nominal 12 Volt fans. Generally, exact replacement fans are only available in the handy thousand-pack.

But armed with nominal size, cfm, and noise generated, you can usually find an equivalent replacement fan with similar specs.

Here is the first site I found from a search that offers a variety of fans. I am sure there are many others.

http://www.quietpcusa.com/Quiet-Computer-Fans.aspx

.

Reply

Answer 2

^Tripper^ Author

Level 1

8 points

Nov 27, 2015 10:21 PM in response to Grant Bennet-Alder

Hi Grant.

Thanks for the info, but as I understand it, that will not work correctly. The Mac fans, although using a 4 pin connector, are not compatible with the standard PC 4pin PWM fans.They do not work in the same way as PC fans - i.e. they vary their speeds depending on a different voltage source compared to PC fans.

I could use one but it’ll probably just run at full speed all the time. Which will be the only choice I have should I not be able to find an apporiate replacement.

Thanks for the help.

Reply

Answer 3

Nov 28, 2015 7:39 AM in response to ^Tripper^

Those fans are not special, except that a simple two-wire fan cannot vary its speed.

The red and black wires are for the input Voltage. When used in a Mac the yellow wire provides an RPM output, and the nominal 12 Volt input Voltage is varied by software running on the System Management Controller to obtain different speeds.

Reply