Cause - Fan is hitting an internal component
If the i-One-series PC is making a noise that sounds like a baseball card placed in the spokes of a bicycle, a fan may be hitting something as it spins. When the unit is tilted all the way either up or down, it may cause one of the fans to come into brief contact with an internal component.
1. To prevent damage to the fan, open the unit and locate the 3 small heat sinks directly adjacent to the CPU socket.
2. Bend each one sightly with the end of a flat-head screwdriver (IMG_2245.JPG).
3. Also ensure that the power cable for each fan is not in the way of the fan blades.