Fujitsu AOYG09KHCAN, Service Manual

Page: 41 / 128

Check point 4. Check serial signal (Forward transfer signal)
Check serial signal (Forward transfer signal)
RED
WHITE
BLACK
+
-
3
2
1
• Check if indicated value swings between AC 30 V and AC 130 V at outdoor unit terminal 2—3.
• If it is abnormal, replace main PCB.
• If it is abnormal, check indoor unit fan motor. (Indoor unit fan motor in "Service parts informa-
tion" on page 03-35)
• If indoor unit fan motor is abnormal, replace indoor unit fan motor and main PCB.
• If it is abnormal, replace outdoor unit main PCB.
↓
End
Check point 1-2. Check external cause such as noise
• Check the complete insulation of the grounding.
• Check if there is any equipment that causes harmonic wave near the power cable (Neon light
bulb or any electronic equipment which causes harmonic wave).
↓
End
2-2. E: 11. Serial communication error (Serial forward transfer error) (Indoor unit)
- (03-5) -
2. Troubleshooting with error code
TROUBLESHOOTING TROUBLESHOOTING