Blocked high density filter at the front side of the projector.

Replace the front high density filter with a new one. See "Cleaning the front dust filter".

Ambient temperature too high.

Check the ambient temperature at the air inlets of the projector. Make sure that the ambient temperature does not exceed 35°C (95°F).

Malfunction air extraction system.

Check the condition of the air extraction system. The air extraction system must be capable of removing minimum 6,65 m³/min or 235 CFM per installed digital projector.