Damaged wire unit of the temperature sensor which measures the temperature of the cooling block of the light pipe entrance.

1. Repair the wire unit.

2. If not repairable, replace the whole wire unit and temperature sensor.

Defect temperature sensor on the cooling block of the light pipe entrance.

Replace the temperature sensor.

Misalignment of the lamp inside the lamp house.

1. Readjust the Z-alignment of the lamp. See "Realignment of the lamp in its reflector".

2. Replace the lamp house with a new lamp house. See "Removal of the lamp house".

Misalignment of the cold mirror.

Readjust the cold mirror. See "Cold mirror assembly".