Fujitsu Comfort Series Service Manual page 48

Troubleshooting 22
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 dose 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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