The lamp house is not correctly installed in its compartment.

Check if the lamp house is properly installed. Ensure that thethree fixation screws (reference S) of the lamp house are fastened.

Switch damaged.

Check lamp house detection switch for damage. The switch islocated behind upper right locking bolt insertion area on projector.Replace if damaged.

Switch disconnected.

Check connection of lamp house detection switch at the PowerBackplane, if connections are OK then measure switch cable for continuity.

Malfunction Fan Control Board.

Replace the Fan Control Board.

Defect Power Backplane.

Replace the Power Backplane.