Cheap fan death-rattle

I buy cheap stuff. Nothing bugs me so much as knowing my money is going down the drain of a middleman’s margin. Two of my best weapons to keep costs down are Aliexpress, for buying wholesale from China, and slickdeals, where readers collaboratively point out how to exploit coupons and price mistakes.

Years ago I was needing a laptop and this Fujitsu LH531 popped up on the latter. It’s out of date now, but at the time this dual i5 was a great deal for $399.

After upgrading to an SSD it has seen heavy use. I might hate this laptop if I paid more money for it. It has a cheap plastic shell and is not especially thin, or light, of elegant. In a word, adequate. However, mine has a special feature: it emits the warm glow of knowing I didn’t pay much.

It always bothered me that its fan is audible. It’s not so bad, but I’m oversensitive. Fan noise can be okay when kept at a consistent low level, but there are only two BIOS settings for this fan, which amount to “be loud all the time” or “be quiet, but constantly cycle on and off”. Third party software and manipulation of the Windows power policies didn’t help. There was also a noticeable rattle when the fan turns off.

As I said, I’m cheap. Because Moore’s law is still in effect, every month I avoid upgrading my laptop means I will be getting that much better a deal on the next one I buy. So I’ve just been putting up with the fan. After all, the only time it really bugs me is when watching a video in a quiet room.

In the back of my head every time I heard this rattle I would think… how could I fix this? I could put my own fan controller in. I could see if replacing the fan would help. I could put in an RC circuit to force it to spin up and down slowly. But this was always while I was watching a video, typically at night when I didn’t feel like starting a new project. Plus laptops can be finicky, and I didn’t feel like destroying one.

But finally I got over it and opened the damn thing up. A few prods with my fingertip showed the problems:

Bad mechanical design. There are only two screws holding the fan in place, and no mechanical buffer between the fan and the heat sink it abuts. So I made an electrical tape bridge across the fan and the heat sink, and pieces of foam tape to wedge the fan in the unconstrained axis perpendicular to the two screws that hold it in place.


The rattle is gone. I gave up a few style points by not using duct tape or rubber bands. Omnia cum pretio.

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