SERVICE MANUAL
R
−
410A Ductless Split System: DLF4(A/H), DLC4(A/H)
68
421 08 9204 00
(8) Communication malfunction: (following AP1 for outdoor unit control board)
Detection:
Is there any damage to the indoor unit mainboard com-
munication circuit? Is communication circuit damaged?
Are the indoor and outdoor units connection wire, and
indoor and outdoor units inside wiring correct or not, is
there any damage?
Fault diagnosis process:
Y
N
Y
N
N
Y
N
N
Y
N
Y
N
Y
Y
Start
Did the equipment operate
normally before the failure
occured?
The AP1 voltage
detection circuit
is at fault
Check wiring inside of
the indoor and outdoor
units
Are wires broken?
Check the communication
circuit of the outdoor unit
If the fault is eliminated?
The communication
circuit is abnormal
Replace the main board
of the indoor unit
End
If the fault is eliminated?
Replace the main board
AP1 of the outdoor unit
If the fault is eliminated?
Is the connection right?
Check the wiring of the indoor and
outdoor units with reference to the
wiring diagram
Correctly connect the
corresponding wires for
the indoor and outdoor
units with reference to
the wiring diagram
