Anyway to repair noisy Apple iMac fan?

[d3v]

Hi all, I've got a mid 2011 21.5" iMac that has a noisy optical drive fan. I've cleaned what little dust that was there but it made no difference.

Availability of a new fan is sketchy, they are all used/refurbished.
Thinking about servicing the internal bearing. Has anyone done this, is it worth trying?

 

[NviGate Systems]

If you have an UltraSonic cleaner you clean the sucker really good then re apply grease. Note you need property grease, NOT WD40 or HouseHold Oil, as these compounds are not designed for service life of a fan.

There are a number of modding sites that sell it. Most are located in China though.

I've had mixed results with refurbs of fans. It depends on the technology in the fan, is; sleeveless, ball bearing etc.

If you can remove the fan assembly to expose more of the assembly, an ultrasonic has a better chance of cleaning. Don't use anything but proper mixtures for PCB parts such as Branson EC or Chemtronics FluxOff. (In Canada FluxOff is the only thing I can import without massive freight charges, it costs $200 in freight to bring Branson EC to Canada!)

 

[d3v]

I was going to clean off the grease with isoproponal alcohol then pack the bearings back inside with some bicycle bearing grease, why the need for such specialist products?

 

[NviGate Systems]

This happens to be what I have. Bycicle grease might work, I don't know if it is the right consistency. If it doesn't work you will have a hard time getting it out.

I bought a small UltraSonic cleaner because they are so handy for cleaning. Whenever I service laptop and even desktops I often throw the heatsink in the ultrasonic. Works wonders for getting smokers lung out of heatsinks.

Anyways, have a go.

 

[sapphirescales]

It's possible that the iMac isn't reducing the fan speed even though the temperature is okay. I've seen this many times. You can use this program to see the temps and if necessary you can manually reduce the fan speed:

http://www.crystalidea.com/macs-fan-control

 

[trevm999]

iMac fans are actually not too expensive, compared to other AIO computers (I've seen new a fan for Lenovo AIO to be $200)

 

[Markverhyden]

iMac fans are actually not too expensive, compared to other AIO computers (I've seen new a fan for Lenovo AIO to be $200)

iFixit has them for $25 for the aforementioned machine. Of course that's in the US.

https://www.ifixit.com/Store/Mac/iMac-21.5"-(EMC-2428)?page=3&display=list

 

[d3v]

It's possible that the iMac isn't reducing the fan speed even though the temperature is okay. I've seen this many times. You can use this program to see the temps and if necessary you can manually reduce the fan speed:

http://www.crystalidea.com/macs-fan-control

Yep already covered this. Temps and RPM's are all normal and fine, it is just a clicking noise as the bearings in the fan are dodgy. This fan should never of passed quality control!

iFixit has them for $25 for the aforementioned machine. Of course that's in the US.

https://www.ifixit.com/Store/Mac/iMac-21.5"-(EMC-2428)?page=3&display=list

Here in the UK can't find ANY in new condition, all used/refurbed!

 

[GTP]

I use " Spray Grease" just a light grease that comes in an aerosol can. It has a "sticky" property that adheres to the bearings. They last a long time afterward.

 

[Markverhyden]

Here in the UK can't find ANY in new condition, all used/refurbed!

iFixit has an EU web presence. I did not see any iMac fans but it never hurts to call.

https://eustore.ifixit.com/en/home/

 

[d3v]

Hey fella's I've had a good success with this..

I disassembled the fan, all I had to do was pry off a tiny circlip which you can see in the photo. There was dry grease that I'm thinking is molybdenum or lithium, so I use a wetwipe to clean it all away then I applied some whitel ighting bicycle bearing grease to all surfaces that I could see were contacting one another, then realised the bearings were sealed in two separate sealed units so I simpply gave each one a sharp tap with a small srewdriver hoping it would knock any stuck ball bearings inside, then finished off by applying a bit more grease between the two sealed bearing cups for good measure.
Thank god the circlip fitted back on OK at the end!

The result - a fan as good as new - completely silent, and I have even stress tested it for 10 minutes at 4350rpm using Mac Fan Control utility.
I'm proud of myself right now!

 

[trevm999]

Maybe I will have to try this for my $200 lenovo fans...

 

[d3v]

Maybe I will have to try this for my $200 lenovo fans...

Do it!