"220V Cooling Fan" air convection occurs when the job to the notebook cooling together, but also the dust in the air to remain in personal appearance and vents near, not only affect the cooling effect and increase the "220V Cooling Fan" load together, also it changed the air convection environment, leading to the occurrence of noise. This representation if timely removal will not affect the occurrence of components; if not timely removal, over time will lead to a fan blade shaft wear occur overnight will incur fan fan shaft wear occurs overnight will incur "220V Cooling Fan" fan shaft wear occurs overnight will lead to the occurrence of a fan blade shaft wear "eccentric", this noise this noise this noise this noise, just replace the cooling fan competence deal with the problem.