[plug] next Installfest?

[Brad Campbell]

Nick Bannon wrote:
> On Sun, Feb 29, 2004 at 01:51:55PM +0800, Jon  Miller wrote:
> 
>>Got a 8-port Netgear and a 24-port (that's noisy due to a fan needing replaced) Netgear. 
>>Anyone know how to repair a noisy fan?
> 
> 
> I'll bring an 8 port gigabit switch... (they're cheap!)
> 
> For fan maintenance, add a few drops of oil, under the sticker, or
> through a drill-hole if necessary. If it's difficult to access, you can
> run the oil down a wire or thread of some sort.

Although this is reasonably sound advice in the short term, a noisy fan is caused by wear in the 
bearings. Despite being a cheap bastard, after years of doing every sort of kludge known to man 
(Even replacing bearings with whatever I could find that would fit) I can honestly say that trying 
to quiet a noisy fan rather than replacing it is false economy.
Fans are cheap compared to the equipment they are protecting. Do yourself a favor and grab a new 
one, preferably with ball bearings rather than sleeves (Although ball bearings are noiser than sleeves).

Bearings are factory lubricated. Balls are usually sealed with a bit of lube in the race and sleeves 
are impregnated with lubrication. As ball bearings wear they generate small bits of metal fragments 
that accelerate the wear process so by the time they get noisy they are well on thier way to a 
catastrophic failure.
Sleeves generate noise generally by wearing in such a way as to allow a resonance in the rotating 
member. A fan is never perfectly balanced, and as a sleeve bearing wears it allows the fan to 
vibrate, causing more wear in the bearing.

Long and short. If you value your gear don't use cheap fans and replace them as they get noisy.

Brad