On Nov 18, 5:48*pm, Ignoramus5827
wrote:
I have a couple of devices with very noisy and annoying fans. One is
an old laptop and another is a car inverter. In both, fans make a very
annoying, inconsistent, and rattling sound. Before taking those things
apart etc, I wanted to double check what is the typical cause of this
and how to deal with them.

i

Rattling is usually bad, means the bearing is going or gone. Can also
be something stuck in the works. Laptops present problems because
fans are usually a custom component, sometimes integrated with a
heatsink and/or heatpipe that feeds from the CPU. There are online
laptop boneyards for some parts, you'd have to google the exact
model. I've had some luck with sleeve-bearing fans taking them apart,
cleaning the shafts and fan blades, then relubing and reassembling
them. I don't use them again in critical locations. Standard size
fans can be had for cheap off the internet, I usually buy them by the
dozen. Noisy ones get replaced as and when needed. Watch the bearing
types, noise and air movement ratings.

Stan