Fujitsu AUXB04GALH Service Manual page 159

Trouble shooting 73
Indoor Unit - No Power
(Wall mounted type)
Check Point 1 : Power supply
Is not the breaker down?
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
Check Point 2 : Fuse or Thermal fuse of Indoor unit
Is not open circuit ?
If the fuse was open state, check the cause of short circuit
on the AC circuit before replacing the spare parts.
NG (Short circuit on AC circuit)
Check Point 3 : Short circuit check on AC circuit
Disconnect AC power input wires and check short circuit
NG (Short circuit on AC circuit)
Check Point 4 : Power supply circut of FAN Motor
Disconnect FAN motor and Check short circuit
NG (Short circuit)
Replace Main PCB
Forecast of Cause :
1. Power Supply failure 2. Outside cause 3. Electrical Component defective
Check Point 5 : Resistor R101
OK
NG (Short circuit ) Check Point 6 : Short circuit check on DC13.5V circuit
Check short circuit between Pin No.1 and Pin No. 6 of CNB01
(DC 13.5V circuit )
1. Disconnect EEV connector
2. Disconnect SP motor
3. Disconnect Wired Remote Controller
4. Disconnect Transmission PCB
Check Point 7 : Short circuit check on DC5.0V circuit
NG (Short circuit )
Check short circuit between Pin No.5 and Pin No. 7 of CN3 (TEST)
(DC 5.0V circuit )
1. Disconnect Indicator PCB
2. Disconnect SW PCB
3. Disconnect Transmission PCB
04-83
Check Resistor R101, Open / Short circuit check
NG
(Open circuit on R101)
OK (Open circuit)
Pin No.1 and Pin No.7 of CN18
OK (Not Open)
2.2 Ohm + 5%
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