Fujitsu ASUG12LZAS Service Manual page 49

Check point 4. Check serial signal (reverse transfer signal)
Check serial signal (Forward transfer signal)
• 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
tion" on page 03-69)
• If indoor unit fan motor is abnormal, replace indoor unit fan motor and main PCB.
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).
2-2. E: 11. Serial communication error (Serial forward transfer error) (Indoor unit)
GREEN
WHITE
N
BLACK
L
RED
3
WHITE
2
BLACK
1
↓
End
↓
End
+
-
- (03-13) -
"Service parts informa-
2. Troubleshooting with error code