Fujitsu AB F18LAT Series Service Instruction page 64

Trouble shooting 31
No Operation (Power is ON)
Check Point 1 : Check indoor and outdoor installation condition
Indoor Unit - Check incorrect wiring between Indoor Unit - Remote Control, or terminals between Indoor Units.
Or, check if there is an open cable connection.
Are these Indoor Unit, Outdoor Unit, and Remote Control suitable model numbers to connect?
>> If there is some abnormal condition, correct it by referring to Installation manual and
Data & Technical Manual.
OK
Turn off Power and check/ correct followings.
Is there loose or removed communication line of Indoor Unit and Outdoor Unit?
OK
Check Point 2 : Check external cause at Indoor and Outdoor (Voltage drop or Noise)
Instant drop ----- Check if there is a large load electric apparatus in the same circuit.
Momentary power failure ----- Check if there is a defective contact or leak current in the power supply circuit.
Noise ----- Check if there is any equipment causing harmonic wave near electric line.
(Neon bulb or electric equipment that may cause harmonic wave)
Check the complete insulation of grounding.
OK OK
Check Point 3 : Check Electrical Components at Indoor and Outdoor
Check Voltage at CN14 of Controller PCB.
(Power supply to Remote Control)
>> If it is DC12V, Remote Control is failure. (Controller PCB is normal)
>> If it is DC 0V, Controller PCB is failure. (Check Remote Control once again) >> Replace Controller PCB
>> If the symptom does not change by above Check 1, 2, 3, replace Main PCB of Outdoor unit.
Forecast of Cause:
1. Setting/ Connection failure 2. External cause
3. Electrical Component defective
02-33
>> Replace Remote Control