Gree GWH09YC-K6DNA1A Service Manual page 65

(8) Communication malfunction: (following AP1 for outdoor unit control board)
Mainly detect:
●Is there any damage for the indoor unit mainboard communication circuit? Is communication circuit damaged?
●Detect the indoor and outdoor units connection wire and indoor and outdoor units inside wiring is connect well or not, if is there any
damage?
Fault diagnosis process:
The AP1 voltage
detection circuit
is at fault
If the fault is eliminated?
Y
62
Y
Check wiring inside of
the indoor and outdoor
units
Are wires broken?
Y
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
Installation and Maintenance
Service Manual