Damaged wire insulation of the temperature sensor which measures the ambient temperature. When disconnecting the wire of the temperature sensor from the Signal Backplane (reference 14 image) the error code is changed to “ambient - temperature sensor open”.

1. Repair the insulation of the of the temperature sensor which measures the heat sink temperature of the blue channel (reference 12 image).

2. If not repairable, replace the temperature sensor and wiring.

Defect temperature sensor (reference 12 image) which measures the ambient temperature. When disconnecting the wire of the temperature sensor from the Signal Backplane (reference 14 image) the error code is changed to “ambient - temperature sensor open”.

Replace the temperature sensor (reference 12 image) which measures the heat sink temperature of the blue channel.