Fujitsu ABYG18KRTA, Service Manual

Page: 78 / 196

Check point 4. Check serial signal (Reverse transfer signal)
Check serial signal (Reverse transfer signal)
RED
BLACK
WHITE
BLACK
WHITE
+
-
N
L
3
2
1
• Check if indicated value swings between AC 90 V and AC 270 V at the outdoor unit terminal 1
—3.
• If it is abnormal, check the parts below.
– Outdoor unit fan motor in "Service parts information" on page 03-46
• If outdoor fan motor is abnormal, replace outdoor unit fan motor and main PCB.
• If the checked parts are normal, replace the 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
2-1. E: 11. Serial communication error (Serial reverse transfer error) (Outdoor unit)
- (03-4) -
2. Troubleshooting with error code
TROUBLESHOOTING TROUBLESHOOTING