MP 1,1-5,1 PSU & Fan Sounds on 2012 Mac Pro 5,1

Nanco

macrumors newbie
Original poster
Jul 3, 2019
4
0
Hi there,

I wondered if someone could help to clarify if the sounds in the following video were normal or potentially a sign of something wrong (headphones recommended):

https://bit.ly/2FJLMij

The PSU is making a fizzing sound up close. The fan is also emitting a low whirring sound that is quite noticeable from a distance, even when the side is on the case.

Any help will be appreciated.

Kind Regards,
Matt
 

Eneco

macrumors member
Jul 1, 2018
99
14
The buzzing of the PSU is somewhat normal. There are some threads about this topic here on the forum and a lot of people confirmed, that their PSU is buzzing. But this can only be heard when being close to the unit. Nothing to worry about.

The fan however sounds like it is out of balance. You could try to remove it and put a drop of oil into the bearing underneath the sticker. That's what I did with my rear exhaust fan and ever since the problem is gone.
 
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donluca

macrumors regular
Jul 30, 2018
183
90
Italy
You could try to remove it and put a drop of oil into the bearing underneath the sticker. That's what I did with my rear exhaust fan and ever since the problem is gone.
Can you kindly go into a little more detail?

After you remove the sticker, do you just let a couple of drops get inside? What kind of oil do you use? Is good ol' WD-40 alright?
 

Eneco

macrumors member
Jul 1, 2018
99
14
*I'm neither a technician nor a native english speaker, so I don't know the right words of the parts*

Every fan within the Mac Pro has a grey sticker on one side, covering the bearing of the fan. Underneath that sticker is a small hole with the shaft of the fan. I just put some drops of oil in there. WD-40 will be fine, at least that's what I used. If the fan's shaft got dried out and is grinding along its bearing creating a wobbling sound, a few drops of oil might help.

This way I also fixed the fan of my Airport Time Capsule which was rattling.
 

Nanco

macrumors newbie
Original poster
Jul 3, 2019
4
0
Thank you for your responses.

I did actually contact a reputable business who handles Apple spares and repairs prior to getting a response in this thread. They also confirmed that this power supply noise was somewhat normal, however they did supply me with a replacement anyway. I can confirm that the replacement is no quieter than my original power supply, so I guess this corroborates the fact that these power supplies are designed to be somewhat noisy. Its barely audible under my desk anyway, but I’m glad to know that this is nothing to worry about.

As for the fan, please excuse my ignorance, but what is the best and correct way to remove the PSU fan? I have never actually done it before.

I did try to remove the little plate that the fan is mounted on to at first (unscrewed two small screws at the bottom of the plate), but this thing appears to be fitted tight. Am I missing something obvious?

I did manage to loosen two of the rubber pins that connect the fan to the plate, though there wasn’t enough room to reach the other two to remove the fan completely (even if I could, I can foresee it being a pain to reattach them).

With that said, I was able to remove the sticker which revealed a silver disc with a tiny copper/brass centre. It appears flush to the plastic fan enclosure and I couldn’t see any holes as such. I’m a bit stuck where to go from here so any further help would be greatly appreciated.

Kind Regards,
Matt