Fujitsu Comfort Series Service Manual page 47

Troubleshooting 25
No Operation (Power is ON)
Check Point 1 : Check hydraulic unit and outdoor unit installation condition
Are these hydraulic unit and outdoor unit 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 hydraulic unit and outdoor unit?
OK
Check Point 2 : Check external cause on units (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.
>> If the symptom does not change by above check 1, 2 replace Main PCB of outdoor unit.
Forecast of Cause:
1. Setting/ Connection failure 2. External cause
3. Electrical Component defective
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