If a fan begins to make a rumbling noise this may indicate a problem with the fan. Fans are essential to maintain optimal operating efficiency of the projector; so it is strongly recommended that the unit be sent in for service to replace the fan.

If it seems like there is something hitting the fan blades it could mean that there is an obstruction in contact with the fan blades. First, try to identify the obstruction visually then try shaking it out if possible. If the noise continues, it is strongly recommended that the unit be sent in for service.

Note: When the high altitude mode is enabled, the fan will operate at a higher RPM, resulting in a slight increase in fan noise