Blocked Lamp Cathode Fan.

Remove the Lamp House and check if the Cathode Fan is not blocked. Ensure that the Cathode Fan can turn freely (reference 1 image).

Damaged wire.

Remove the Cathode Fan assembly and check if the wire of the Cathode Fan is not damaged. Repair if possible, otherwise replace with new one (reference 3image).

Lamp Cathode Fan end of life.

Replace the Lamp Cathode Fan. See service manual chapter "Replacement of the Lamp Cathode Fan".

Malfunction Cinema Controller.

Replace the Cinema Control board. See service manual chapter "Replacement of the Cinema Controller".