I think I just killed a fan...

liivahiir

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I was just cleaning my system and when I got to the fans, I just used the vacuum cleaner to suck on them. This of course spun them up in the process and it was quite effective at removing the dust.

All the fans work except for one really old one. I have no idea what the brand is, it's just a leftover from an old case. It does have "colorful" written on it, could that be it?

Anyways, it seems that it's getting power, but doesn't have enough to keep spinning. It's fully stopped, and when I spin it up manually, it will make a quiet whiny noise, probably indicating that the engine is still half alive. Spinning the fan the opposite way doesn't generate this sound. It also spins a bit longer than usual before stopping.

So I guess this way of cleaning maybe isn't the best? :lol:

Or maybe it's just the fan's fault, as it is a very old one and all the others worked perfectly.
 
Fan motors generate electricity when you spin them, you are lucky you haven't caused more damage by overloading the mobo, ditch the fan, get a new one and don't vacuum a Pc without static precautions and unplugging the fans first :)
Moto
 

dscudella

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Never use the vacuum cleaner. Ever. Moving parts generate static electricity which can and will fry your components. Go to Walmart or Target and get a can or two of compressed air. Don't shake it, just spray.
 

liivahiir

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Oh wow, didn't know you could damage the mobo that way, thanks :)

As for the vacuum cleaner, I took the fans out and cleaned them while they were far away from the computer, so I doubt static electricity from the dust could have caused any problems in that way.

I've used a small brush to clean the mobo, is that okay? Compressed air would still be faster though.
 

liivahiir

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Well, I don't think I unplugged all of them. Can't remember, so there still was a chance. Although, I did keep my finger on them while I was doing that, so that they wouldn't go completely crazy spinning. Maybe they did't even go too much above the normal fan speed, so it would have been fine. There's no real way to know, it was still a happy accident. Not doing that again ;)
 

liivahiir

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Well, I meant to say spinning the fan without actually powering it :) As I described before, you can clean fans VERY easily by simply vacuuming them and sort of letting them spin. So basically you're not using the moto, you're just spinning the blades. The danger of course is that you might spin it them too fast, I'm curious if this is a risk. Yes, you can restrict the blades while vacuuming, which would slow down the fan to a reasonable speed, but as always, accidents happen. :D

Not sure if there are any fan experts lurking around here that could answer such a question :p Thanks for your help btw! This forum is really awesome!
 

groundrat

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All electrical motors are basically inverted generators. Motors use windings of copper wire and induced voltage to turn a metal shaft. Generators take the movement of a metal shaft and convert it to AC current/voltage. Yes, spinning up a fan does generate voltage. No, I have never seen it fry a motherboard.

A good way to protect a motherboard from any possibility of damage from movement generated current is by using a fan controller that isn’t plugged into the motherboard.

Most likely the fan just died due to old age. They do that. All fans have a lifespan that is listed on the product packaging.

Alternatively you could have broke the fan if while cleaning it if your vacuum sucked to hard on the cowling. Once a fans cowling becomes separated from the motor assembly, it’s done. They are only glued on.

 
Just spinning it without it being plugged into anything won't hurt anything no,
I have a sideline cleaning Pc's out and I always unplug/block fans from moving when I vacuum them
but if you look at a fan, by spinning the blades with your fingers or a vacuum you move the magnets around the coil which is in the centre of the hub, this generates electricity, if that current has somewhere to go, I.e. a wire, it will travel down the wire as far as it can,
but you couldn't spin it fast enough with your fingers to cause problems, a vacuum may provide sufficient rotation speed to cause damage
Moto
 

larkspur

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There's really no danger to the fan if you vacuum it. Your old fan is probably just dead. The whining sound is likely a dead bearing. I only use a vacuum cleaner to clean the outside of my case and my dust filters. The fans themselves I clean about once a year when I open her up and blow all of the dust out of everything (heatsinks, mobo, fans, etc) using compressed air.

So my advice is to use the vacuum only externally while using canned air on everything inside (including the fans). It helps your wife/girlfriend not freak out if you are outside when you blow all the dust out ; )
 

chugot9218

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I am fairly sure I have read that compressed air or a vacuum cleaner can spin the fans faster then their bearings are designed to go, which can damage them, completely dependent of any electrical issue. Wherever I read it suggested using a toothpick (or something else non-conducive) to hold the fans still while you blow them out.
 

liivahiir

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Thanks for all of your replies!

So yeah, using compressed air for fans while also unplugging them seems the safest bet. I have a feeling that it was the vacuuming that broke the fan. The fact that it was pretty old probably helped too. Not a big loss, fortunately. That thing was doing nearly nothing anyways.

Morale of this story: Vacuuming fans is dangerous, people.
 
G

Guest

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Right, so I wired up a PWM 12v fan to a multimeter, blasted it flat out with compressed air from a Compressor ( Industrial unit used to Spray paint/ Run Tyre Change Machine)

Fan spun way way way faster than it ever could plugged in ( It was literally screaming) and generated 3.4v at max. this is way under the 12v connection it is plugged into.

Myth busted, spinning the fan fast plugged in WILL NOT produce enough voltage to damage the Motherboard.

BTW, The fan is now dead, bearings have gone from High revolutions (it was an old fan anyway)
 

chugot9218

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Cool, glad someone can give us real life examples! I did not think it would produce enough voltage to damage the MOBO but I certainly believe you can damage the bearings.
 
G

Guest

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Tested a new fan (Fractal 120mm) with a vacuum cleaner, got 2.84v (used all the attachments, but cleaning nozzle spun it the fastest.)

Bearings were fine after, (These being ball not sleeve like the last fan )