After I installed a working fan in a power supply, I had two broken 120mm 12VDC fans on my hands. One with a bad bearing which needed replacing, and another one which was going to be the replacement until my clumsiness destroyed it. I've taken apart similar fans before so I didn't expect any surprises, but it's always interesting to see how different companies solve similar problems.

The fan with growling bearing is by Yate Loon Electronics. It's very hard to read very much more detail out of the label because its center has been distorted into a faded shiny bubble. I presume this is result of friction heat generated by the failing bearing.

Back of the label is consistent with heat damage. I had expected to see the motor shaft at this point but there's a soft red rubber seal I had to remove first.

There's plenty of lubricant visible, too bad none of this was in the right place to do much good.

Popping off the white plastic split ring allowed the fan to come apart. I saw no visible wear to explain the noise this fan had been generating. At some point in the future I hope to have the knowledge to know what to look for, which may require magnification equipment.

A closer view of the core of the fan. It is securely fastened to the plastic base.

I found no fasteners or clips to release, so I went with brute force: using large pliers to rip the core off the base to see the back of the circuit board.

The other fan was functionally fine until I accidentally broke a fan blade. It was made by Poweryear and they have no fault for this. It was entirely my clumsiness.

Under the label was a hard plastic seal. I was surprised to see this, it meant I could not access the plastic split ring (or functional equivalent) to disassemble the fan.

I went straight to ripping the core assembly off the chassis, unintentionally breaking another fan blade in the process. I still couldn't get to the back side of this fan's axle. Teardown foiled!

No matter, sleeve bearings fail and I'm sure I'll have more dead 120mm cooling fans in the future. For now I can harvest my first 140mm fan from a misbehaving power supply.