Wire unit (reference 1 image "Cold mirror fan connection") of the Cold Mirror fan (reference 2 image "Cold mirror fan connection") disconnected.

Remove the left cover of the projector and check the connection of the wire unit of the fan below the Cold Mirror.

Wire unit of the fan units (reference 5 image "Cold mirror fan connection") disconnected from the Signal Backplane.

Remove the front cover and front dust filter from the projector and check if the wire unit (reference 5 image "Cold mirror fan connection") is inserted in the Signal Backplane.

Blocked fan (reference 2 image "Cold mirror fan connection").

Unblock the fan. Ensure that the fan can turn freely.

Damaged wire unit.

Check if the wire unit of the fan is not damaged. Repair if possible, otherwise replace with new one.

Malfunction Fan Control board.

Replace the Fan Control board. See "Removing a board in the card cage".

Fan end of life.

Replace the fan. See chapter "Cold mirror fan".