Communication Malfunction - Gree GWC09QB-K3DNB2B Service Manual

8. Communication malfunction: (following AP1 for outdoor unit control board)
Mainly detect:
The AP1 voltage
Y
detection circuit
is at fault
If the fault is eliminated?
Y
58
Y
Check wiring inside of
the indoor and outdoor
units
Are wires broken?
N
Check the communication
N
circuit of the outdoor unit
The communication
circuit is abnormal
N
Replace the main board
of the indoor unit
Start
Did the equipment operate
normally before the failure
occurs?
Y
Replace the main board
Y
AP1 of the outdoor unit
If the fault is eliminated?
N
Y
End
N
Check the wiring of the indoor and
outdoor units with reference to the
wiring diagram
Is the connection right?
N
N
Correctly connect the
corresponding wires for
the indoor and outdoor
units with reference to
the wiring diagram
If the fault is eliminated?
Y
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