Gree GWH07AFAXA-K3NNA1A Service Manual page 77

9. Communication malfunction E6
Main detection points:
● Check if the connection wire and the built-in wiring of indoor and outdoor unit are connected well and without damage;
● If the communication circuit of indoor mainboard is damaged? If the communication circuit of outdoor mainboard (AP1) is damaged?
Malfunction diagnosis process:
Malfunction of
circuit is
detected with Y
control board
AP1 voltage
If the malfunction
is removed?
Y
Note: method for checking the communication circuit of outdoor unit: cut off the communication wires of indoor/outdoor unit, and
then measure the voltage between COM and N of the control board of outdoor unit (DC notch, about 56V)
74
Y
Check built-in wiring
of indoor and
outdoor unit
If the wiring is
damaged?
N
Check communication
N
circuit of outdoor unit
Problem of
communication
circuit
N
Replace indoor
board
Start
If the unit is operation
normal before
malfunction
Y
Replace outdoor
Y
mainboardAP11
If the
malfunction is
removed?
N
Y
End
Service Manual
N
Check connection
wire of indoor and
outdoor unit with
circuit diagram
Connection
correct?
N
Check connection
wire of indoor and
outdoor unit with
circuit diagram
If the malfunction
is removed?
Installation and Maintenance