1, "220V Cooling Fan" normal rotation, but the cooling effect is not good: This is more common in small radiator, the reason is very simple, it is filled with dust between the fins. Then you need to be removed to the fan, the radiator cleaned with a brush on it.
    2, about the situation cpu cooling fan may need to be replaced
. a "220V Cooling Fan" rotation not working: This is oil bearing common problem, because that is bearing into the dust, lost lubricating fluid lubrication.
 . b noise suddenly become great: encountered this problem, the first order is that there is not a fan blade cracked.
  . c When "220V Cooling Fan" turned a lot of noise, turn one will quiet down: this phenomenon is more common in the winter. The reason is the lubricating fluid got into the dust, in the cold state viscosity becomes large, it will lose lubrication. After use for some time because the friction and heat, lubricating fluid after heating increased mobility, he has returned to normal.