What kind of sound can indicate an issue with fan bearings?

A whining sound can indicate an issue with fan bearings because it typically signifies that the bearings are experiencing friction or insufficient lubrication. When bearings begin to wear out or become damaged, they may grind together, creating the high-pitched whining noise. This sounds distinct from normal operational noise and typically changes in pitch or intensity with varying speeds of the fan. Addressing this issue promptly is critical to prevent further mechanical failure or catastrophic damage to the fan assembly.

In contrast, the other sounds listed are generally associated with different issues. For example, a clicking sound might indicate a misaligned component or debris caught in the fan, while a hissing sound could suggest air leaks or other aerodynamics issues. Additionally, a Gregg sound is not a standard term used in this context and may refer to specific situations not relevant to fan bearings.