Fujitsu AU A36LCLU Series Service Instruction page 81

Trouble shooting 37
No Operation (Power is ON)
Check Point 1 : Check indoor and outdoor installation condition
Indoor unit - Check incorrect wiring between indoor unit - remote controller, or terminals between indoor units.
Or, check if there is an open cable connection.
Are these indoor unit, outdoor unit, and remote controller suitable model to connect?
>> If there is some abnormal condition, correct it by referring to manual.
OK
Is there loose or removed serial communication line of between indoor unit and outdoor unit?
OK
Check Point 2 : Check external cause at indoor unit and outdoor unit(Voltage drop or noise)
Instant voltage drop of power supply ----- Check if there is abnormally large load in the same power supply system.
Momentary power failure ----- Check if there is a defective contact or leak current in the power supply system.
Noise ----- Check if there is any equipment causing harmonic wave near electric line.
(Neon bulb or electric equipment that may cause harmonic wave)
Check whether the ground connection is proper.
OK
Check Point 3 : Check electrical components at indoor unit and outdoor unit
Check voltage at CN6(AR*C36-54LCTU) and CN14(Other indoor unit)
>> If it is DC12V, Wired Remote Controller is failure. >> Replace Wired Remote Controller
>> If it is DC 0V, Controller PCB is fallure. >> Replace Controller PCB
>> If Check Point 1, 2 do not improve the symptom, replace control parts of outdoor unit.
Forecast of Cause:
1. Setting / Connection failure 2. External cause
3. Electrical component defective
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