Desktop computer fan started making noise then stopped.
We noticed it requires 12V and will run at 200mA. I wasn't sure about that at first. Does that mean it has an internal resistance of : 12V / 200mA = 60 Ohms?
If so that means I could supply it with 12V and it would consume 200mA and spin.
Question: Is that what I should assume from reading those details on the fan?
I decided to try it out with a bench power supply, but first I decided to measure how much resistance I could read.
Check Fan Resistance
When I hooked up my meter to read resistance I read 20 KOhms of resistance. Hmmm...?? Well, wasn't sure about that because if it were true then 12V would only supply it with only 0.6mA (600uA) and I knew that wouldn't work properly.
I applied 12V to it figuring nothing lost here since it wasn't working. The the fan just barely moved then stopped.
I'm assuming the fan is dead, but I have a couple of questions.
What are the "normal" reasons these fans die? Dirt?
What generally makes these fans die? There really aren't any parts touching anything to wear out are there?
Is there any way to bring it back? (extreme cleaning of some sort? - blowing out dust or is it carbon build-up or something?)
Does the high resistance (20 KOhms) indicate that the fan is dead or would a working fan read that amount also?
One Last Interesting Point
After I was done testing it I put it back in the desktop case and hooked the computer's power to it again and it started spinning slowly 20-30 rpm or so (guessing). Why would it do that?